Head to head
Testosterone cypionate against Testosterone enanthate
The two standard injectable esters, effectively interchangeable in effect. The differences that matter are practical: an eight day half-life that makes a single weekly shot peak and crash, and the fact that only one of them has an approved weekly auto-injector.
Column A
Testosterone cypionateTestosterone cypionate, long-chain injectable ester
The most prescribed injectable testosterone in the United States. Its eight-day half-life is why a single weekly shot produces a peak and a crash, and why splitting the same total flattens the curve.
Column B
Testosterone enanthateTestosterone enanthate, long-chain injectable ester
The other standard injectable ester, effectively interchangeable with cypionate. It has one thing cypionate does not: an approved weekly auto-injector.
Side by side, on the facts we can check
| Attribute | Testosterone cypionate | Testosterone enanthate |
|---|---|---|
| Category | Hormone | Hormone |
| FDA status | FDA-approved as Depo-Testosterone for male hypogonadism. Schedule III controlled substance. Not approved for women or for age-related low testosterone in men with normal levels. | FDA-approved for male hypogonadism, including as a weekly subcutaneous auto-injector. Schedule III controlled substance. The auto-injector carries a boxed warning for blood pressure increases. |
| Half-life | Roughly 8 days. That single number is the argument: at an eight-day half-life, a fortnightly interval spans nearly two half-lives, so levels at the end of the cycle are a fraction of the peak. | Roughly 7 to 8 days, close enough to cypionate that the two behave alike in practice. |
| Molecular weight | 412.6 Da. A steroid ester, not a peptide. | 400.6 Da. A steroid ester, not a peptide. |
| Mechanism | Testosterone esterified at the 17-beta hydroxyl with cyclopentylpropionic acid, which makes it lipophilic enough to remain in an oil depot at the injection site. Tissue esterases cleave the ester gradually to release free testosterone, so the ester chain length governs the release rate rather than the activity. Once cleaved, the hormone is identical to endogenous testosterone and acts at the androgen receptor, with the same conversions to dihydrotestosterone by 5-alpha-reductase and to oestradiol by aromatase. Peak-to-trough variation across a dosing interval is a property of the ester and the interval, not of the molecule's potency. | Testosterone esterified with enanthic acid, a seven-carbon chain, giving an oil-soluble depot that tissue esterases cleave gradually. Once cleaved the hormone is indistinguishable from endogenous testosterone. The slightly shorter chain than cypionate gives a marginally faster release in theory, and the difference has not been shown to matter clinically. |
| Human studies cited | 1 | 1 |
| Legal status, US | FDA-approved, prescription only | FDA-approved, prescription only |
Frequently asked questions
What is the difference between Testosterone cypionate and Testosterone enanthate?
Testosterone cypionate: The most prescribed injectable testosterone in the United States. Its eight-day half-life is why a single weekly shot produces a peak and a crash, and why splitting the same total flattens the curve. Testosterone enanthate: The other standard injectable ester, effectively interchangeable with cypionate. It has one thing cypionate does not: an approved weekly auto-injector.
Which has stronger research evidence, Testosterone cypionate or Testosterone enanthate?
This database does not grade compounds. It counts what was run in people: 1 of the 2 studies cited on the Testosterone cypionate profile were human work, against 1 of 2 for Testosterone enanthate. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Testosterone cypionate and Testosterone enanthate FDA-approved?
Testosterone cypionate: FDA-approved as Depo-Testosterone for male hypogonadism. Schedule III controlled substance. Not approved for women or for age-related low testosterone in men with normal levels.. Testosterone enanthate: FDA-approved for male hypogonadism, including as a weekly subcutaneous auto-injector. Schedule III controlled substance. The auto-injector carries a boxed warning for blood pressure increases..
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.