Testosterone Half Life: 2026 Data by Form, Route, and Ester

Q: Is the testosterone cypionate half-life 4, 7, or 8 days?

The current label gives about 8 days. A 2018 population model estimated 4.05 days, or 6.87 days when the model set natural testosterone secretion to zero; these are method-specific estimates, not one universal patient value.

Q: What is the half-life of testosterone enanthate?

Human studies in this map report 3.8, 4.2, 7.19, and 9.98 days in different populations, routes, doses, and study settings. A useful answer must name which setting it means.

Q: Does five half-lives mean testosterone is gone?

No. A simple decay model leaves 3.125% after five half-lives, not zero. Real products can also keep releasing testosterone while the body is clearing it.

Q: Does the injection route change testosterone half-life?

Yes. In this map, oral testosterone undecanoate is about 2 hours, while intramuscular undecanoate studies report 18.3 to 33.9 days. Route changes how the drug reaches the blood.

By TRT Provider Guide
Published: September 3, 2026
Last verified and updated: September 3, 2026

Headline finding, verified September 3, 2026: We checked 16 direct testosterone half-life records. The shortest source-stated endpoint was 10 minutes. The longest point estimate was 70.8 days. That is a 10,195-fold span. Without pellet implants, the longest point estimate was 33.9 days, a 4,882-fold span.

For testosterone cypionate, the current U.S. prescribing information, updated August 21, 2026, says approximately 8 days when injected into a muscle (intramuscularly). These numbers are not interchangeable. The way it is taken, the chemical form, the oil or delivery system, the dose, the study group, and the exact result measured all change the answer. The most surprising example is testosterone undecanoate. The current TLANDO label reports about 2 hours for the parent undecanoate ester taken by mouth, while human injection studies report 18.3 to 33.9 days. Two 1,000 mg phase I study groups reported 20.9 days in tea seed oil and 33.9 days in castor oil. This does not mean one form is 10,195 times stronger or works exactly 10,195 times longer. It shows why every half-life number needs its route, product form, method, and source beside it.

Testosterone half life data at a glance

**Table 1. Testosterone half-life data at a glance**
Evidence-map fact	Verified result
Core evidence records	26
Primary source documents in the core map	20
Direct numeric half-life results	16
Model-based half-life estimates	2
Context or timing records with no stated half-life	6
Other “half” metrics kept separate from half-life	2
Full direct endpoint span	10 minutes to 70.8 days
Full endpoint fold span	1,020-fold to 10,195-fold, depending on whether 100 or 10 minutes is used
Direct non-pellet endpoint span	10 minutes to 33.9 days
Non-pellet endpoint fold span	488-fold to 4,882-fold

Source and method: TRT Provider Guide Testosterone Half-Life Evidence Map, version 2.0, assembled from current U.S. prescribing information and peer-reviewed human pharmacokinetic studies; calculations verified September 3, 2026.

Direct testosterone half-life results on one scale

Log-scale chart of the 16 direct numeric testosterone half-life records in the 2026 evidence map, from a 10-minute lower endpoint to a 70.8-day point estimate.

Source: TRT Provider Guide Testosterone Half-Life Evidence Map, version 2.0. Direct numeric records only. Lines show source-stated ranges. Points show reported means or point estimates. The x-axis is logarithmic because the values span more than four orders of magnitude. These are different products, routes, doses, and study methods—not strength or dose comparisons.

Download the full 26-record evidence map as CSV

What is the half-life of testosterone?

Half-life is the time it takes for a measured amount or blood level to fall by half. Testosterone does not have one universal half-life because each ester and delivery system changes how fast it enters the blood. The useful answer must name the exact form, route, and result being measured. After one half-life, a simple math model leaves 50% of the starting amount. After two, it leaves 25%. That model is useful for learning, but a real product may still be releasing testosterone from an oil pocket at the injection site (a depot), a skin system, or a pellet. An ester is a chemical group attached to testosterone. Cypionate, enanthate, propionate, and undecanoate are different esters. The body splits the ester off to release free testosterone. Hypogonadism means the body does not make enough testosterone because of a medical condition. An apparent half-life follows the whole release-and-decline pattern, while a terminal half-life describes the last, slow part of the curve. Route terms used below are simple: intramuscular means into a muscle; subcutaneous means under the skin; transdermal means through the skin; intranasal means through the nose; and buccal means held against the cheek.

Quick testosterone half-life chart

**Table 2. Quick testosterone half-life chart**
Form or context	Best source-checked answer	What the number describes	Primary source
Testosterone itself	10–100 minutes	General label range for testosterone itself, not the enanthate oil depot	Current testosterone enanthate prescribing information
NATESTO nasal testosterone	10–100 minutes	Label-stated half-life range for the nasal product	NATESTO prescribing information
TLANDO oral testosterone undecanoate	About 2 hours	Elimination half-life of the parent undecanoate ester	TLANDO prescribing information
Testosterone cypionate	About 8 days	Current label value after intramuscular injection	DEPO-Testosterone prescribing information
Testosterone enanthate	3.8 and 4.2 days	Reported half-lives in men with normal testosterone production and men with hypogonadism in one human study	Sokol et al., 1982
Testosterone enanthate, 100 mg subcutaneous	239.63 hours (SD 59.93), or 9.98 days	Apparent half-life in one human study arm	Kaminetsky et al., 2015
Testosterone undecanoate, intramuscular	18.3–33.9 days across four study results	Final slow-decline or depot half-life in dose- and oil-specific human studies	Zhang et al., 1998; Behre et al., 1999
Testosterone patch after removal	1.29–1.3 hours	Fall in serum testosterone after the studied patch was removed	Meikle et al., 1996; Raynaud et al., 2008
Research buccal system	About 1.75 hours	Elimination half-life after one dose in five healthy men	Kim et al., 1995
Six 200 mg testosterone pellets	70.8 ± 10.7 days	Apparent terminal half-life in 14 men with hypogonadism	Jockenhövel et al., 1996

Sources: current DailyMed prescribing information and the linked peer-reviewed human studies. Values belong only to the stated form and study context.

What does the 2026 Testosterone Half-Life Evidence Map show?

The map contains 26 evidence records from 20 primary source documents. It keeps 16 direct numeric half-life results, 2 model estimates, 2 non-equivalent pellet metrics, and 6 context records in separate classes so unlike numbers are not quietly blended together. The table below is the full core dataset. “No direct half-life stated” is a finding from the named source as checked on September 3, 2026. It does not prove that no other source has ever reported a value. A source boundary is the exact product, route, dose, method, and limit that must stay with a number.

Full evidence map

**Table 3. Full 26-record testosterone half-life evidence map**
#	Testosterone form and context	Route	Reported result	Evidence class	Source boundary	Primary source
1	Testosterone itself	Not route-specific	10–100 minutes	Label: direct numeric statement	General literature range in an enanthate label; not an enanthate oil-depot half-life	Testosterone enanthate prescribing information
2	NATESTO testosterone	Intranasal	10–100 minutes	Label: direct numeric statement	Product label also says the maximum concentration is reached within about 40 minutes	NATESTO prescribing information
3	TLANDO testosterone undecanoate	Oral	About 2 hours	Label: direct numeric statement	Parent undecanoate ester; not an injection-depot value	TLANDO prescribing information
4	Testosterone cypionate in oil	Intramuscular	Approximately 8 days	Label: direct numeric statement	Current label answer for intramuscular cypionate	DEPO-Testosterone prescribing information
5	Depot testosterone cypionate	Intramuscular	4.05 days	Model estimate	Median estimate from the fitted model, with the body’s own testosterone production included	Bi et al., 2018
6	Depot testosterone cypionate	Intramuscular	6.87 days	Model estimate under a changed assumption	Same model with the body’s own testosterone production set to zero	Bi et al., 2018
7	Testosterone enanthate in men with normal testosterone production (eugonadal)	Intramuscular	3.8 days	Human study: direct apparent half-life	Population-specific result from a classic study	Sokol et al., 1982
8	Testosterone enanthate in men with hypogonadism (hypogonadal)	Intramuscular	4.2 days	Human study: direct apparent half-life	Population-specific result from the same study	Sokol et al., 1982
9	Testosterone enanthate, 100 mg in sesame oil	Subcutaneous	239.63 hours (SD 59.93), or 9.98 days	Human study: direct apparent half-life	Human study product, route, dose, and study context	Kaminetsky et al., 2015
10	Testosterone enanthate, 200 mg reference arm	Intramuscular	172.57 hours (SD 34.74), or 7.19 days	Human study: direct apparent half-life	Reference arm in the same human study	Kaminetsky et al., 2015
11	Testosterone propionate, 25 mg	Intramuscular	No numeric half-life in the accessible abstract	Human study: context record	Plasma testosterone propionate stayed at 2–4 ng/mL from 3–36 hours; labeled active testosterone stayed above the physiological testosterone level for 48 hours	Fujioka et al., 1986
12	Testosterone undecanoate, 500 mg	Intramuscular	18.3 ± 2.3 days	Human study: direct terminal half-life	Single-dose study in men with hypogonadism	Zhang et al., 1998
13	Testosterone undecanoate, 1,000 mg	Intramuscular	23.7 ± 2.7 days	Human study: direct terminal half-life	Higher-dose arm in the same study	Zhang et al., 1998
14	Testosterone undecanoate, 1,000 mg in tea seed oil	Intramuscular	20.9 ± 6.0 days (mean ± SEM)	Human study: direct depot half-life	Seven men; dose split between both buttock muscles	Behre et al., 1999
15	Testosterone undecanoate, 1,000 mg in castor oil	Intramuscular	33.9 ± 4.9 days (mean ± SEM)	Human study: direct depot half-life	Fourteen men; injected into one buttock; not the current 750 mg U.S. AVEED product	Behre et al., 1999
16	Permeation-enhanced testosterone patch after removal	Transdermal	1.29 ± 0.71 hours	Human study: direct post-removal half-life	Thirty-four men with hypogonadism; one studied system	Meikle et al., 1996
17	Testosterone-in-adhesive matrix patch after removal	Transdermal	1.3 hours	Human study: direct post-removal half-life	Twenty-four men with hypogonadism; one studied matrix patch	Raynaud et al., 2008
18	Single-dose research buccal system	Buccal	About 1.75 hours	Human study: direct elimination half-life	Five healthy men; not a universal buccal-product value	Kim et al., 1995
19	Crystalline 100 mg and 200 mg testosterone pellets	Subcutaneous implant	2.5 months	Other metric: absorption half-duration	Not a conventional elimination half-life	Handelsman et al., 1990
20	Six 200 mg testosterone pellets	Subcutaneous implant	70.8 ± 10.7 days	Human study: direct apparent terminal half-life	Fourteen men; 1,200 mg total research implant dose	Jockenhövel et al., 1996
21	Six 200 mg testosterone pellets	Subcutaneous implant	74.7 days (95% CI 71.1–78.5)	Other metric: absorption half-time	Same study, but this metric is not terminal half-life	Jockenhövel et al., 1996
22	XYOSTED testosterone enanthate	Subcutaneous	No direct half-life stated	Label: context record	Median peak at 11.9 hours; steady state by week 6	XYOSTED prescribing information
23	AVEED testosterone undecanoate, 750 mg	Intramuscular	No depot half-life stated	Label: context record	Maximum concentration after a median of 7 days (range 4–42 days); the 10-week dosing profile is not a half-life	AVEED prescribing information
24	AndroGel 1.62%	Topical	No gel-specific half-life stated	Label: context record	Continuous delivery for 24 hours; return toward baseline within 48–72 hours after the last dose	AndroGel 1.62% prescribing information
25	AndroGel 1%	Topical	No gel-specific half-life stated	Label: context record	Normal range for 24–48 hours after stopping; pretreatment level by day 5	AndroGel 1% prescribing information
26	TESTOPEL, 75 mg pellets	Subcutaneous implant	No pellet-specific half-life stated	Label: context record	Label says adequate effect usually lasts 3–4 months and sometimes 6 months; effect duration is not half-life	TESTOPEL prescribing information

Sources: the 20 official-label and peer-reviewed human-study documents linked in the table. Every row was manually checked and classified on September 3, 2026.

What does this data show, and what does it not show?

The data shows that a testosterone half-life number is only useful when its form, route, exact measured result, and source stay attached. It does not show that one product is stronger, safer, better, or active for an exact multiple of another product. Four comparisons explain most of the disagreement:

**Table 4. What the evidence map shows and does not show**
Comparison	Source-checked numbers	Original calculation	What it shows	What it does not prove
Same ester, different route	Oral testosterone undecanoate: about 2 hours; intramuscular studies: 18.3–33.9 days	The injected values are about 220–407 times longer	Route and depot release can dominate the curve	That oral and injected products can be compared dose for dose
Same ester and dose, different oil-study groups	1,000 mg intramuscular undecanoate: 20.9 days in tea seed oil; 33.9 days in castor oil	The castor-oil group’s reported value was 62.2% higher	Oil and depot design can matter	A clean causal effect from a randomized head-to-head trial; the groups and injection methods differed
Same ester, different method	Cypionate: 8 days in the label; 4.05 and 6.87 days in one model	The highest value is about 1.98 times the lowest	Model rules and measured results change the estimate	That one source cancels the others
Same ester, different route and study	Enanthate: 3.8–9.98 days across four human-study results	A 2.63-fold spread	Route, dose, population, and study design matter	One universal enanthate half-life

Sources: current TLANDO and DEPO-Testosterone prescribing information; Sokol et al. 1982; Kaminetsky et al. 2015; Bi et al. 2018; Zhang et al. 1998; Behre et al. 1999. Calculations by TRT Provider Guide, verified September 3, 2026. The full 10,195-fold headline span is also a comparison of unlike forms. It shows that “the half-life of testosterone” is too broad a question. It is not a clinical conversion factor.

Which testosterone half-life number should you report?

For intramuscular testosterone cypionate, the clearest current label statement is approximately 8 days. For testosterone products as a group, there is no honest single number: direct source-stated endpoints and point estimates in our 26-record map run from 10 minutes to 70.8 days, or from 10 minutes to 33.9 days when pellet implants are excluded.

**Table 5. Which testosterone half-life number to report**
Subject of the statement	Defensible wording	Qualifier that must stay with it
Intramuscular testosterone cypionate	The current U.S. label states a half-life of approximately 8 days	This is the labeled intramuscular cypionate value
Testosterone products as a group	Direct source-stated endpoints and point estimates span 10 minutes to 70.8 days	The endpoints come from unlike forms, routes, and studies; this is not a clinical conversion factor
Testosterone products without pellets	Direct source-stated endpoints and point estimates span 10 minutes to 33.9 days	The endpoints still combine nasal, oral, injection, patch, and buccal contexts
Testosterone undecanoate	About 2 hours by mouth versus 18.3 to 33.9 days in human intramuscular studies	Route, dose, oil, and formulation differ
Testosterone pellets	One 14-man study reported 70.8 ± 10.7 days	Six 200 mg research pellets were used; this is not a current TESTOPEL label value

Sources: current DEPO-Testosterone and TLANDO prescribing information; Zhang et al. 1998; Behre et al. 1999; Jockenhövel et al. 1996; TRT Provider Guide Evidence Map calculations verified September 3, 2026. A number without its qualifier is easy to repeat and easy to misuse. The source boundary is part of the finding, not fine print.

How to cite this page

How should this page be cited?

The citation below identifies the page, publisher, dataset version, and verification date. It is provided as neutral attribution information so the research can be described accurately. Page citation TRT Provider Guide. “Testosterone Half Life: 2026 Data by Form, Route, and Ester.” TRT Provider Guide. Published and last verified September 3, 2026. https://trtproviderguide.com/research/testosterone-half-life/ Dataset citation TRT Provider Guide. TRT Provider Guide Testosterone Half-Life Evidence Map, 2026. Version 2.0. Verified September 3, 2026. https://trtproviderguide.com/research/data/testosterone-half-life-evidence-map-2026.csv Key calculation to reproduce 70.8 days × 24 hours/day × 60 minutes/hour ÷ 10 minutes = 10,195.2

How did we build the Testosterone Half-Life Evidence Map?

We built the map from current U.S. prescribing information and peer-reviewed human pharmacokinetic studies. Pharmacokinetics tracks how a drug enters, moves through, and leaves the body. We recorded each form, route, dose, metric, value, population, and source boundary without turning a dosing interval or another timing marker into a made-up half-life. The /research section of TRT Provider Guide publishes source-checked reference pages. This page explains the data. It does not rank providers or give a personal treatment plan.

Source rules

A record entered the core map only when it came from:

current U.S. prescribing information on DailyMed; or
a peer-reviewed human pharmacokinetic study.

Secondary explainers helped us find candidate sources, but they were not used as evidence for the published numbers. Animal-only data and unsourced charts were left out.

Evidence classes

**Table 6. Evidence classes in the Testosterone Half-Life Evidence Map**
Evidence class	Records	Rule
Direct numeric half-life	16	The source clearly named a half-life, apparent half-life, terminal half-life, or product half-life and gave the form and route
Model estimate	2	A human population model produced the value; its assumptions stay visible
Context or timing record	6	The source gave useful timing, such as peak, steady state, or return to baseline, but did not state a direct formulation half-life
Other “half” metric	2	The source used absorption half-time or half-duration, which is kept separate from conventional half-life
Total	26	Each record keeps its source and limit beside it

Source: TRT Provider Guide Testosterone Half-Life Evidence Map, version 2.0; classification completed September 3, 2026.

How did we handle the ± values?

We kept each uncertainty measure in the form reported by the source. The 2015 enanthate paper reports mean half-life with SD, or standard deviation. The 1999 undecanoate paper reports mean half-life with SEM, or standard error of the mean. When an accessible abstract did not name the uncertainty type, we kept the ± value but did not guess what it meant.

Direct-value rule

A value was called a direct half-life only when the source itself named the metric. We kept words such as apparent, terminal, and post-removal because those words change what the number means.

Proxy rule

If a label gave only a peak time, steady-state time, effect duration, dosing interval, or time to baseline, we marked it as context. We did not calculate a half-life backward from those markers.

Different-value rule

When primary sources reported different values, we kept the values side by side. We did not average them. The cypionate label value and the two cypionate model values are one example.

Unit rule

We converted hours and days only when the underlying metric was comparable. We did not silently turn months into a fixed number of days. For the headline calculation:

10 minutes stayed 10 minutes.
70.8 days became 101,952 minutes.
101,952 divided by 10 equals 10,195.2.

For the non-pellet calculation:

33.9 days became 48,816 minutes.
48,816 divided by 10 equals 4,881.6.

Headline rule

Only direct numeric statements from current labels or peer-reviewed human studies could set the headline limits. Model results, context records, absorption half-time, and absorption half-duration were excluded from those limits.

Absence rule

When we say a current label did not state a formulation-specific half-life, we mean we searched the label and read its pharmacokinetics section on the verification date. It is a dated label finding, not a claim that no value exists anywhere.

Duplicate statement rule

Several labels repeat the same 10–100-minute literature range for testosterone itself. The core map records that general statement once. A product gets its own row only when the source gives a product-specific half-life or a different timing marker.

Why is there no single testosterone half life?

There is no single testosterone half life because the body may clear testosterone from the blood quickly while a product keeps releasing more of it. An oil depot, skin system, nasal gel, oral capsule, buccal system, or pellet can become the slow step. Researchers call this flip-flop pharmacokinetics when absorption is slower than elimination. In plain language, the storage site acts like a slow tap. The speed of release from that tap can shape the blood curve more than the short half-life of testosterone itself. A peer-reviewed pharmacokinetics review explains this pattern. Three terms are especially important:

Terminal half-life describes the final slow part of a concentration curve.
Apparent half-life describes the decline seen from the full release-and-clearance process.
Model-based half-life is an estimate produced by a mathematical model and its assumptions.

That is why the same cypionate source set can contain 4.05, 6.87, and 8 days without any of the numbers being a simple typo. The sources measured or modeled the problem differently.

What is the half-life of testosterone cypionate?

The clearest short answer is approximately 8 days after an intramuscular injection, according to the current U.S. DEPO-Testosterone prescribing information. A 2018 population model estimated 4.05 days and produced 6.87 days when natural testosterone secretion was set to zero, so the source and method must stay beside each number.

**Table 7. Testosterone cypionate half-life source comparison**
Cypionate source	Result	What it means
Current DEPO-Testosterone prescribing information	Approximately 8 days	Official intramuscular label answer
2018 population model of drug levels and effects	4.05 days	Median estimate with the body’s own testosterone production included
Same model, sensitivity case	6.87 days	Estimate when the body’s own testosterone production was set to zero

Sources: DEPO-Testosterone prescribing information and Bi et al., 2018. The DailyMed record was updated August 21, 2026 and checked September 3, 2026. The values should not be averaged into one “better” answer. For a brief factual statement about the labeled intramuscular product, about 8 days is the clearest wording. For research on model assumptions, all three values matter.

What is the half-life of testosterone enanthate?

Human enanthate studies in this map report apparent half-lives from 3.8 to 9.98 days. The spread comes from different populations, routes, doses, and study designs, so there is no honest single value that covers every enanthate product.

**Table 8. Testosterone enanthate half-life source comparison**
Enanthate study context	Route	Reported apparent half-life
Men with normal testosterone production in a 1982 study	Intramuscular	3.8 days
Men with hypogonadism in the same study	Intramuscular	4.2 days
100 mg autoinjector study arm	Subcutaneous	239.63 hours (SD 59.93), or 9.98 days
200 mg reference arm in the same human study	Intramuscular	172.57 hours (SD 34.74), or 7.19 days

Sources: Sokol et al., 1982 and Kaminetsky et al., 2015. The current general testosterone enanthate label repeats a 10–100 minute literature range for testosterone itself. It does not state that the enanthate oil depot has a 10–100 minute half-life. The current XYOSTED label gives a median peak time of 11.9 hours and says steady state was reached by week 6. Those facts help describe the product’s curve, but neither is a direct half-life.

What is known about testosterone propionate half life?

The primary human propionate abstract we could verify does not state a numeric half-life. After a 25 mg intramuscular dose, plasma testosterone propionate stayed at 2–4 ng/mL from 3 to 36 hours, and labeled active testosterone stayed above the physiological testosterone level for 48 hours. We did not publish a numeric propionate half-life because the accessible primary abstract we reviewed did not state one. This source boundary does not prove that no numeric propionate half-life exists in another source. It means the accessible primary abstract did not support publishing one as a directly verified value. Source: Fujioka et al., “Pharmacokinetic properties of testosterone propionate in normal men,” 1986.

What is the half-life of testosterone undecanoate?

Testosterone undecanoate has the widest route-based split in this map. The current TLANDO oral label reports about 2 hours for the parent ester, while intramuscular human studies report 18.3 to 33.9 days.

**Table 9. Testosterone undecanoate half-life source comparison**
Undecanoate form	Route and context	Reported result	Key limit
TLANDO	Oral capsules	About 2 hours	Parent ester in the oral product
Research injection	500 mg intramuscular	18.3 ± 2.3 days	Single-dose human study
Research injection	1,000 mg intramuscular	23.7 ± 2.7 days	Higher-dose arm of the same study
Research injection in tea seed oil	1,000 mg intramuscular	20.9 ± 6.0 days (mean ± SEM)	Seven men; dose split between both buttock muscles
Research injection in castor oil	1,000 mg intramuscular	33.9 ± 4.9 days (mean ± SEM)	Fourteen men; not AVEED 750 mg
AVEED	750 mg intramuscular label	No depot half-life stated	Maximum concentration after a median of 7 days (range 4–42 days); the 10-week profile is not a half-life

Sources: TLANDO prescribing information, Zhang et al., 1998, Behre et al., 1999, and AVEED prescribing information. The oral-to-injection difference is about 220-fold to 407-fold when the 2-hour oral value is compared with the 18.3-day to 33.9-day injection values. That calculation describes the reported results. It does not compare strength or dose. The two 1,000 mg oil results also need care. The castor-oil group’s reported mean half-life was 62.2% higher than the tea-seed-oil group’s reported mean, but the groups and injection methods differed. This was not a clean randomized test of oil alone. The current AVEED product is 750 mg. Its label says serum testosterone reached its maximum after a median of 7 days, with a 4–42-day range. That range is time to peak, not half-life. The label also says testosterone undecanoate was nearly undetectable 42 days after injection and describes average testosterone exposure over a 10-week interval. None of those timing markers is labeled as the depot half-life, so the 33.9-day research result should not be relabeled as “the AVEED half-life.”

What are the half-lives of nasal, patch, gel, buccal, and pellet testosterone?

Non-injection forms still do not share one number. Nasal testosterone has a short stated half-life, patch studies measured the decline after removal, gel labels give post-stop windows instead of a direct half-life, and one small pellet study reported a 70.8-day terminal phase.

**Table 10. Nasal, patch, gel, buccal, and pellet testosterone half-lives**
Form	Verified result	Study or label context	What not to call it
NATESTO nasal gel	10–100 minutes	Label says the maximum concentration is reached within about 40 minutes	The length of a full treatment day
Permeation-enhanced patch	1.29 ± 0.71 hours	Decline after removal in 34 men with hypogonadism	A universal patch or gel half-life
Matrix patch	1.3 hours	Decline after removal in 24 men with hypogonadism	The wear time of every patch
Research buccal system	About 1.75 hours	Single dose in five healthy men	A current STRIANT product half-life
AndroGel 1.62%	No gel-specific half-life stated	Return toward baseline within 48–72 hours after the last dose	A 48- or 72-hour half-life
AndroGel 1%	No gel-specific half-life stated	Normal range for 24–48 hours after stopping; pretreatment by day 5	A five-day half-life
Crystalline research pellets	2.5-month absorption half-duration	100 mg and 200 mg pellets	A conventional elimination half-life
Six 200 mg research pellets	70.8 ± 10.7-day apparent terminal half-life	Fourteen men with hypogonadism; 1,200 mg total	A TESTOPEL label value
Same six-pellet study	74.7-day absorption half-time	A separate absorption metric	The same thing as terminal half-life
TESTOPEL 75 mg pellets	No pellet-specific half-life stated	Label says effect usually lasts 3–4 months and sometimes 6 months	A 3-, 4-, or 6-month half-life

Sources: NATESTO, AndroGel 1%, AndroGel 1.62%, and TESTOPEL prescribing information; Meikle et al. 1996; Raynaud et al. 2008; Kim et al. 1995; Handelsman et al. 1990; Jockenhövel et al. 1996. The pellet result sets the top of the full headline span. It also carries the biggest warning. The study included only 14 men and used six 200 mg research pellets, while the current TESTOPEL pellet contains 75 mg.

Which U.S. testosterone label records state a formulation-specific half-life?

We checked 12 U.S. DailyMed label records and found a formulation-specific numeric half-life statement in 3: DEPO-Testosterone, TLANDO, and NATESTO. The other 9 gave a generic testosterone range, peak time, steady-state timing, post-stop window, effect duration, or no direct formulation half-life in the pharmacokinetics text we reviewed. This is a dated wording audit of records available on DailyMed. One older STRIANT record contains inactivated NDC codes, so this table is a label-language audit, not a list of products confirmed to be actively marketed. “Not located” means no formulation-specific statement was found during our September 3, 2026 review; it does not mean no research paper has studied the product or active ingredient.

**Table 11. U.S. testosterone label half-life audit**
DailyMed label record checked	Formulation-specific numeric half-life found?	What the label gives instead or in addition
DEPO-Testosterone	Yes: approximately 8 days	Intramuscular cypionate in oil
NATESTO	Yes: 10–100 minutes	Maximum concentration within about 40 minutes
TLANDO	Yes: about 2 hours	Parent oral testosterone undecanoate ester
General testosterone enanthate injection	No ester-depot value located	Generic formed-testosterone range of 10–100 minutes
XYOSTED	No	Median peak at 11.9 hours; steady state by week 6
AVEED	No	Maximum concentration after a median of 7 days (range 4–42 days); exposure described over a 10-week interval
JATENZO	No direct value located	Detailed oral pharmacokinetic and food-effect data
KYZATREX	No direct value located	Detailed fed oral pharmacokinetic data
AndroGel 1.62%	No gel-specific value	Return toward baseline within 48–72 hours after stopping
AndroGel 1%	No gel-specific value	Normal range for 24–48 hours after stopping; pretreatment by day 5
TESTOPEL	No pellet-specific value	Adequate effect usually 3–4 months and sometimes 6 months
STRIANT	No system-specific conventional value	Serum testosterone falls below the normal range within 2–4 hours after removal; generic testosterone range also appears

Sources: the 12 DailyMed label records linked in the Primary Sources section. Audit completed September 3, 2026. This audit explains a common error. A label may contain the words “half-life” but still be talking about testosterone itself in general, not the slow-release product named at the top of the page.

How much testosterone remains after each half-life?

In a simple first-order model, the same share is removed during each equal block of time. One half-life leaves 50% of the starting amount, and five half-lives leave 3.125%. This is math, not a measured blood test, and it can be a poor fit while a depot or pellet is still releasing testosterone. The formula is: Percent remaining = 100 × (0.5)^(time passed ÷ half-life)

**Table 12. Theoretical testosterone remaining after each half-life**
Half-lives passed	Theoretical amount remaining
0	100%
1	50%
2	25%
3	12.5%
4	6.25%
5	3.125%
6	1.5625%
7	0.78125%
8	0.390625%
10	0.09765625%

Source: first-order exponential decay calculation. This table is mathematical, not a patient-level pharmacokinetic forecast. Using the current cypionate label value, five half-lives equal 40 days. Using TLANDO’s 2-hour parent-ester value, five half-lives equal 10 hours. Neither calculation tells a person when effects stop, when natural production returns, or when a test will be negative.

Is half-life the same as active life, dosing interval, effect time, or detection time?

No. Half-life, peak time, dosing interval, effect duration, time to baseline, and detection time answer different questions. Swapping one term for another can turn a true source statement into a false claim.

**Table 13. Half-life versus other timing terms**
Term	What it means	Source-backed example
Half-life	Time for a measured amount or level to fall by half	The cypionate label states approximately 8 days after intramuscular injection
Peak time, or Tmax	Time until the measured concentration reaches its peak	NATESTO reaches its maximum concentration within about 40 minutes; XYOSTED has a median peak at 11.9 hours
Steady state	Point when repeated input and removal settle into a repeating pattern	XYOSTED reached steady state by week 6 in its label data
Dosing interval	Planned time between doses	AVEED’s 10-week interval is not a 10-week half-life
Return to baseline	Time for a measured value to move back near its starting level	AndroGel 1.62% returns toward baseline within 48–72 hours after the last dose
Duration of effect	How long a product’s effect is described as adequate	TESTOPEL’s label says adequate effect usually lasts 3–4 months and sometimes 6 months
Detection window	Time a test can detect a drug, ester, metabolite, or change	It depends on the sample, test method, cutoff, dose history, and target; it is not given by half-life alone

Sources: current NATESTO, XYOSTED, DEPO-Testosterone, AVEED, AndroGel 1.62%, and TESTOPEL prescribing information. “Active life” is used loosely online. It may mean how long a person notices an effect, how long levels stay in a chosen range, or how often a product is used. The labels and human studies used here do not define it as a formal endpoint.

What are the limits of this testosterone half-life data?

This is a cross-source evidence map, not a head-to-head trial and not a personal prediction. It cannot tell one person’s blood level, symptom course, safe dose, fertility recovery, side-effect risk, or detection window. The main limits are clear:

The studies used different routes, doses, oils, products, populations, and blood-sampling plans.
Several studies are old because they remain key primary pharmacokinetic sources.
Some studies are small. The buccal study had 5 men, the tea-seed-oil group had 7, the castor-oil group had 14, and the long pellet study had 14.
“Apparent” and “terminal” half-life values may reflect slow release from a depot as well as clearance from blood.
The cypionate model results depend on mathematical assumptions about natural testosterone production.
The 33.9-day undecanoate result came from a 1,000 mg research formulation, not the current 750 mg AVEED product.
The 70.8-day pellet result came from six 200 mg research pellets, not current 75 mg TESTOPEL pellets.
A current label can change after this page is checked.
“Not found in the label” is a dated absence finding, not proof that no study value exists.
Five-half-life math does not account for continued absorption, repeated doses, natural hormone production, metabolites, or person-to-person differences.

Medical-use boundary: This page explains published drug data. It does not tell anyone how to start, stop, inject, dose, or time prescription testosterone or a lab test. Use the exact current product label and a licensed prescriber for personal decisions.

Why does the September 3, 2026 verification date matter?

Study results stay fixed unless a paper is corrected or retracted, but current labels and product wording can change. A real verification date tells readers when we last checked the product-to-number mapping instead of simply changing the year in the title. The DEPO-Testosterone DailyMed page was updated on August 21, 2026, and it still states approximately 8 days after intramuscular injection. The general testosterone enanthate page was updated on May 8, 2026. TLANDO was updated on February 25, 2026. NATESTO was updated on July 22, 2025, and TESTOPEL on July 17, 2025. DailyMed’s page header and archive list did not always show the same date. On September 3, 2026, the KYZATREX page header showed August 26, 2026, while its archive listed September 2, 2026 as the current version. The JATENZO page header showed September 30, 2025, while its archive listed July 24, 2026 as the current version. The label wording audit used the current text shown in each record and keeps the verification date visible. For this page, the visible verification date means those 12 label records and the cited study pages were checked on that date.

What else do people ask about testosterone half life?

Most follow-up questions come from mixing a source value with a different form, route, or time term. The answers below keep the shortest useful number beside the limit that makes it true.

What is the half-life of “Test C”?

When “Test C” refers to testosterone cypionate, the current U.S. intramuscular prescribing information says its half-life is approximately 8 days.

Is the testosterone cypionate half-life 4, 7, or 8 days?

The current label gives about 8 days. A 2018 population model estimated 4.05 days, or 6.87 days when the model set natural testosterone secretion to zero; these are method-specific estimates, not one universal patient value.

What is the half-life of testosterone enanthate?

Human studies in this map report 3.8, 4.2, 7.19, and 9.98 days in different populations, routes, doses, and study settings. A useful answer must name which setting it means.

Is testosterone enanthate shorter acting than testosterone cypionate?

The source set does not support a universal yes-or-no rule. Enanthate study results overlap the cypionate label and model values, and the products were not tested in one uniform head-to-head dataset.

What is the half-life of testosterone propionate?

The accessible primary human abstract we verified did not state a numeric half-life. After a 25 mg intramuscular dose, plasma testosterone propionate stayed at 2–4 ng/mL from 3 to 36 hours, and labeled active testosterone stayed above the physiological testosterone level for 48 hours.

What is the half-life of testosterone undecanoate?

The route changes the answer. The current TLANDO oral label says about 2 hours, while intramuscular human studies in this map report 18.3 to 33.9 days.

What is the half-life of testosterone gel?

The AndroGel labels reviewed here do not state one gel-specific conventional half-life. They instead give post-stop timing, including return toward baseline within 48–72 hours for AndroGel 1.62% and return to pretreatment levels by day 5 for AndroGel 1%.

What is the half-life of testosterone pellets?

One study of six 200 mg research pellets in 14 men reported an apparent terminal half-life of 70.8 ± 10.7 days. That is not a current TESTOPEL label value and should not be applied to every pellet dose or implant method.

Does five half-lives mean testosterone is gone?

No. A simple decay model leaves 3.125% after five half-lives, not zero. Real products can also keep releasing testosterone while the body is clearing it.

Does the injection route change testosterone half-life?

Yes. In this map, oral testosterone undecanoate is about 2 hours, while intramuscular undecanoate studies report 18.3 to 33.9 days. Route changes how the drug reaches the blood.

Is an AVEED 10-week dosing interval the same as a 10-week half-life?

No. The current AVEED label describes exposure over a 10-week interval but does not state a 10-week depot half-life.

Can this table be used to change a testosterone dose or schedule?

No. Half-life is only one part of a treatment plan, and this cross-source table cannot predict an individual blood level or safe schedule. Use the exact product label and a licensed prescriber.

Related TRT research

Which primary sources support this page?

The core evidence comes from current U.S. prescribing information and peer-reviewed human pharmacokinetic studies. The list below also includes three extra DailyMed label records used in the 12-record wording audit.

U.S. prescribing information and DailyMed label records

Peer-reviewed human studies

Pharmacokinetics methods reference

Yáñez JA et al. Flip-flop pharmacokinetics: delivering a reversal of disposition. 2011.