Last updated 25 August 2026.
Enclomiphene is not an FDA-approved drug. It is available as a compounded medication, prepared by a licensed pharmacy for an individual patient on the prescription of a licensed clinician. Compounded medications are not reviewed by FDA for safety, effectiveness or quality before being dispensed. This page is educational. It is not medical advice, and whether any treatment is appropriate for a particular person is a decision for a state-licensed clinician.
Enclomiphene is one of the more misunderstood things sold in men’s health, starting with what kind of molecule it is. This page sets out what it actually is, what the research demonstrates, what it does not, and where it stands with the FDA.
Enclomiphene is not a peptide
Worth correcting first, because a lot of people search for it that way. The confusion comes from it being sold through the same channels as actual peptides, not from anything about the molecule.
Enclomiphene is a small molecule of roughly 405 daltons. It contains no amino acids and no peptide bonds. It belongs to a class called selective estrogen receptor modulators. A peptide is a chain of amino acids joined by peptide bonds. Enclomiphene is not one, and nothing about how it works resembles how a peptide works.
Specifically it is the trans isomer of clomiphene citrate. Clomiphene is a mixture of two geometric isomers, and the FDA-approved labelling for clomiphene describes that mixture as containing between 30% and 50% of the cis isomer, called zuclomiphene, with the remainder being the trans isomer, enclomiphene.
How it works, and how that differs from testosterone replacement
The two approaches are close to opposites, which is the genuinely interesting part.
| Testosterone replacement | Enclomiphene | |
|---|---|---|
| What it supplies | Testosterone from outside the body | Nothing. It acts on the body’s own signalling |
| Effect on LH and FSH | Suppressed | Increased |
| Mechanism | Replaces | Stimulates the existing pathway |
| Needs an intact pituitary and testicular axis | No | Yes |
Enclomiphene blocks estrogen receptors at the hypothalamus. Because estrogen is part of the feedback loop telling the brain to slow testosterone production, blocking that signal raises pituitary output of LH and FSH, which stimulates the testes.
That last row matters more than it looks. Because the mechanism works by stimulating an existing pathway, enclomiphene does nothing for primary hypogonadism, where the problem is in the testes themselves. It is aimed at secondary hypogonadism, where the signalling is the problem.
What the research actually shows
The fertility finding, which is well supported
This is the clearest and most replicated result in the literature. Two Phase III trials compared enclomiphene against a topical testosterone gel and placebo in overweight men with low testosterone, over 16 weeks:
| Enclomiphene | Testosterone gel | Placebo | |
|---|---|---|---|
| Sperm concentration change, trial 1 | +11.7% | -56.6% | +4.1% |
| Sperm concentration change, trial 2 | +15.2% | -32.8% | +7.6% |
| LH and FSH | Increased | Decreased | Little change |
A separate Phase II trial found oligospermia, meaning a low sperm count, developed in 54% of the topical testosterone group compared with 14.6% of the enclomiphene groups. A 2025 systematic review and meta-analysis of ten randomised trials found a relative risk of oligospermia of 0.10 for this drug class compared with testosterone gel.
So the claim that enclomiphene raises testosterone without the fertility cost seen with testosterone replacement is supported by trial evidence, not just by mechanism.
On raising testosterone, it performs comparably rather than better
That same 2025 meta-analysis found no significant difference in total testosterone between this drug class and testosterone gel. The difference between the two approaches is not how high testosterone goes. It is what happens to LH, FSH and sperm along the way.
What the research does not show
We are going to be direct here, because the gap between what is demonstrated and what is commonly claimed is wide.
- There is no long-term safety data. The longest adequately powered randomised trial ran 16 weeks. Across the entire published randomised literature, roughly 191 men have received enclomiphene. Two larger open-label safety studies were run and their results do not appear to have been published.
- Every head-to-head comparison is against testosterone gel, not injections. There is no randomised trial of enclomiphene against injectable testosterone, which is the form most men in the US actually use.
- No trial measured pregnancy or live birth. The fertility endpoint in every study is sperm concentration, which is a surrogate for the thing people actually care about.
- There is no cardiovascular outcome data, no long-term prostate data, and conflicting evidence on bone density.
- Whether raised testosterone from enclomiphene produces the same symptomatic benefit as testosterone replacement has not been established.
The evidence supports a fertility claim. It does not support a safety claim. Anyone telling you enclomiphene is safer than testosterone replacement is going beyond the data, because the comparative long-term safety study has never been done.
Where it stands with the FDA
Enclomiphene is not FDA-approved for any indication, and the reason is specific rather than vague.
- It was developed as a product called Androxal and submitted to FDA in February 2015.
- On 1 December 2015 FDA issued a Complete Response Letter. FDA stated the design of the Phase 3 studies was no longer adequate to demonstrate clinical benefit, and recommended additional trials. FDA also raised concerns about study entry criteria, titration and bioanalytical method validation.
- In January 2018 the European Medicines Agency committee issued a negative opinion on the same application.
Worth being precise about what that means. The drug was not rejected on safety grounds. FDA declined to accept the trial design as demonstrating a benefit that matters to patients, as distinct from a change in a blood test. That is a meaningful distinction and it cuts both ways.
Separately, enclomiphene citrate appears in Category 1 of FDA’s list of bulk drug substances nominated for use in compounding under section 503A, on the list updated 14 May 2026. Category 1 means FDA does not currently intend to take action against compounders using it, subject to conditions. It is not approval, not endorsement, and it is revocable.
Dosing in the published trials
There is no FDA-approved dose, because there is no approved product. The doses appearing in published human trials are 12.5 mg and 25 mg taken orally once daily, with 6.25 mg also studied in an early trial. The Phase III programme used 12.5 mg daily, increasing to 25 mg if testosterone remained low at week six.
Maximum documented exposure in a controlled trial is around six months. What dose suits any individual is a decision for the prescribing clinician, not something to settle from a web page.
Who it may not suit
- Men with primary hypogonadism. The mechanism needs a working pituitary and testicular axis. If the testes are the problem, stimulating them harder does not help.
- Men over 60. The Phase III trials capped enrolment at 60, so there is no trial data above that age.
- Anyone with an untreated cause of low testosterone. Secondary hypogonadism can have causes that need finding rather than working around.
- Athletes and service members. Clomiphene appears on the anti-doping prohibited list under hormone and metabolic modulators, and both clomiphene and enclomiphene appear on the Department of Defense prohibited supplement ingredients list.
What we offer
Testosterone
| Treatment | Monthly | 3 months | Works out at | You save |
|---|---|---|---|---|
| Enclomiphene | $139 | $387 | $129/mo | 7% |
| Injectable Testosterone | $139 | $387 | $129/mo | 7% |
| TRT Cream | $139 | $387 | $129/mo | 7% |
Prices pulled live from our catalogue on page load, so this table cannot go out of date.
A clinician reviews your bloodwork and history and decides whether treatment is appropriate. Our page on what needs a clinic and what does not covers how the process works, and the pricing page lists everything else.
Common questions
Is enclomiphene a peptide?
No. It is a small molecule of about 405 daltons, in a class called selective estrogen receptor modulators. It contains no amino acids.
Is enclomiphene FDA approved?
No. It received a Complete Response Letter from FDA in December 2015 and was never approved. It is available as a compounded medication.
Does enclomiphene affect fertility the way testosterone replacement does?
The trial evidence indicates it does not reduce sperm concentration the way topical testosterone did in the same studies, and sperm counts rose slightly on enclomiphene in those trials. That is the best-supported finding about it.
Is it safer than testosterone replacement?
That has not been tested. There is no comparative long-term safety trial, and the longest adequately powered study of enclomiphene ran 16 weeks.
Will it work if my testicles are the problem?
No. It works by increasing the signal from the pituitary, which only helps if the testes can respond to that signal.
How long can you take it?
Nobody knows. The longest documented exposure in a controlled study is around six months, and no published data exists beyond that.
References
- Kim ED, McCullough A, Kaminetsky J. Oral enclomiphene citrate raises testosterone and preserves sperm counts in obese hypogonadal men, unlike topical testosterone. BJU Int. 2016;117(4):677-685. PMID 26496621
- Wiehle RD, Fontenot GK, Wike J, et al. Enclomiphene citrate stimulates testosterone production while preventing oligospermia: a randomized phase II clinical trial comparing topical testosterone. Fertil Steril. 2014;102(3):720-727.
- Wiehle R, Cunningham GR, Pitteloud N, et al. Testosterone restoration using enclomiphene citrate in men with secondary hypogonadism. BJU Int. 2013;112(8):1188-1200. PMID 23875626
- Kaminetsky J, Werner M, Fontenot G, Wiehle RD. Oral enclomiphene citrate stimulates the endogenous production of testosterone and sperm counts in men with low testosterone. J Sex Med. 2013;10(6):1628-1635. PMID 23530575
- Hohl A, Chavez MP, Pasqualotto E, et al. Clomiphene or enclomiphene citrate for the treatment of male hypogonadism: a systematic review and meta-analysis of randomized controlled trials. Arch Endocrinol Metab. 2025;69(5):e250093. PMC12510335
- Repros Therapeutics. Receipt of Complete Response Letter from FDA for enclomiphene, 1 December 2015.
- FDA. Bulk drug substances nominated for use in compounding under section 503A, updated 14 May 2026.
What we dispense is Enclomiphene, a compounded preparation prescribed for an individual patient after an intake.
General educational information about a medication. Not medical advice, not a recommendation to take anything, and not a claim about effectiveness. Prescription decisions are made by state-licensed clinicians.
