RESEARCH ENCLOMIPHENE 25MG
An isomer of clomifene that acts at oestrogen receptors in the hypothalamus. Not authorised as a medicine or a food supplement in the UK or EU. Supplied for laboratory research use only — read the evidence section below before you decide.
WHAT IS
ACTUALLY KNOWN
We would rather you bought with your eyes open than not at all. Here is the state of the evidence, including the parts that do not help us.
What it is
This is a selective oestrogen receptor modulator. An isomer of clomifene that acts at oestrogen receptors in the hypothalamus.
State of the evidence
Studied in clinical trials. Not licensed for this indication in the UK.
Known risks
It acts directly on the endocrine axis. Use without blood work and clinical monitoring is not something we will guide you through.
Regulatory status
Not authorised as a medicine or a food supplement in the UK or EU.
Status in sport
Selective oestrogen receptor modulators are on the WADA Prohibited List.
What we verify
Identity and purity, per batch, by a laboratory we do not own. We verify what is in the capsule — nothing about what it does.
SPEC SHEET
What is in the bottle, and what is on the certificate.
Enclomiphene
25mg per capsule, as stated on the certificate of analysis for the batch.
Bottle contents
Each bottle contains 60 capsules.
Research use only
We do not publish a human dosing schedule for this compound.
Independently assayed
Each batch is assayed by Janoshik Analytical, an independent laboratory. The Certificate of Analysis for your batch is available on request.
This product is supplied for laboratory research use only. We do not provide dosing instructions, cycle lengths or post-cycle protocols for human use.
ENCLOMIPHENE
Tax included · assayed per batch
WHAT WE CAN
PROVE
We don't have customer reviews to show you yet, and we're not going to invent any. Here is what we can actually put in front of you instead.
Assayed by a lab we don't own
Batches go to Janoshik Analytical, an independent testing laboratory. We don't choose the result.
Tested per batch, not per year
A certificate from a batch made two years ago says nothing about the pack in your hand.
Batch number on the pack
Email it to us with the product name and we'll send the Certificate of Analysis for that batch.
QUESTIONS, ANSWERED
An isomer of clomifene that acts at oestrogen receptors in the hypothalamus. Studied in clinical trials. Not licensed for this indication in the UK.
This product is supplied for laboratory research use only. We do not provide dosing instructions, cycle lengths or post-cycle protocols for human use.
We do not give post-cycle therapy advice. This is a question for a qualified clinician, not for a shop.
No. This acts on your hormonal axis and belongs in a consultation with blood work, not a shopping basket. Ask a doctor.
Yes — identity and purity, per batch, by Janoshik Analytical. Email us the batch number from your pack and we will send that batch's Certificate of Analysis. You do not need to have bought anything to ask.
Sold as a research compound for laboratory and educational use. Not a medicine; not evaluated by the MHRA, EMA or FDA; not intended to diagnose, treat, cure or prevent any disease. Not for human consumption. Not for use by anyone under 18 or by women who are pregnant or breastfeeding.
COMPOUND MONOGRAPH
Enclomiphene in the UK: buying, legal status and what to check
Whether enclomiphene can be bought legally in the UK comes down to what is being sold, and on what basis. Enclomiphene holds no MHRA marketing authorisation. The US application was withdrawn in 2015 after the FDA raised concerns about the trials, a European application under the name EnCyzix was not approved, and the manufacturer discontinued development in 2021. It is a prescription medicine in some countries. A 2026 British Society for Sexual Medicine statement called it unlicensed in the UK and did not recommend routine clinical use outside specialist or research settings (Foster 2026). Here it is sold as a research compound, supplied by FreeMuscle LTD, Scunthorpe, to adults aged 18 or over for laboratory use only.
It is often filed under "uk sarms" or "uk peptides" but is neither: it is a selective oestrogen receptor modulator (SERM), CAS 15690-57-0. A trustworthy UK listing shows:
- the compound and its isomer, since "clomiphene" describes a different product;
- the strength per capsule, and whether it refers to the citrate salt or the free base;
- a batch number on the pack that matches a certificate from a named laboratory;
- plain packaging, tracked delivery, an 18+ condition of sale and no dosing or outcome promises.
This listing states 25 mg per capsule and 60 capsules, and every batch is assayed by Janoshik Analytical, with the certificate sent by email on request. UK delivery is free, tracked and in plain packaging; orders placed before 2pm Monday to Friday are processed the same working day, and EU delivery takes 3 to 7 working days. Terms: shipping and guarantee.
Capsules compared with tablets and other forms
Tablets and capsules raise a practical question: whether a certificate can describe the unit you hold. A capsule holds a weighed powder fill with no compression, so a laboratory can empty capsules and measure each against the stated 25 mg. A tablet is pressed with binders that the assay must extract the compound from. A liquid of a lipophilic molecule like this one relies on a solvent such as ethanol or polyethylene glycol, and its concentration depends on the compound staying in solution, which can change with temperature and time. None of this concerns what a form does, only whether the label figure can be checked.
Enclomiphene compared with clomifene
Comparing enclomiphene with clomifene means comparing a single isomer with the mixture that contains it. Clomifene combines two geometric isomers: enclomiphene, the trans or (E) form, and zuclomiphene, the cis or (Z) form. They share one formula and differ only around a carbon-carbon double bond, yet zuclomiphene is cleared far more slowly. In 15 men taking clomifene long term, the median serum ratio of zuclomiphene to enclomiphene was 20 to 1, so the longer-lived isomer dominated (Helo 2017). Several of the authors worked for the company developing enclomiphene.
A retrospective review of 66 men at one US centre, moved from clomifene to enclomiphene, found no statistically significant difference in median testosterone change, a smaller oestradiol change with enclomiphene and fewer documented adverse effects such as reduced libido, reduced energy and mood changes (Saffati 2024). Every patient took enclomiphene second rather than in random order, and doses were not reported.
Clomifene is a licensed prescription-only medicine in the UK; enclomiphene has no UK licence. In sport they do not differ: both are prohibited at all times. The enclomiphene collection lists every brand stocked, and Enclomiphene vs clomifene: what the trials report covers the controlled trials. How enclomiphene compares with testosterone therapy is a clinical question for a doctor, not a shop.
Reading the certificate of analysis for this product
For enclomiphene, identity has a second question: is it the right isomer. Enclomiphene and zuclomiphene share a formula and a molecular weight of 406.0, so mass spectrometry alone cannot reliably tell them apart. HPLC can, because the two isomers elute at different retention times, and the main peak is matched to a reference standard of the (E) isomer. On the Janoshik certificate for your batch, check:
- Identity: the compound named as enclomiphene, not simply clomifene, with the method used (HPLC, LC-MS or both).
- Purity: the main peak as a percentage of all detected material. Here the impurity that matters most is zuclomiphene.
- Content: the amount measured per capsule against the stated 25 mg, expressed as citrate salt or free base. The free base is roughly two thirds of the mass of the citrate, so the distinction changes the number.
- Batch number and test date: matching your label, and showing the age of the result.
A missing field means that property is unconfirmed, not assumed. If the certificate does not say how the isomers were distinguished, email us and ask what the laboratory reported. See reading a certificate of analysis and our lab testing.
Detection, sport and testing
Enclomiphene is prohibited in sport at all times, in and out of competition. Section S4 of the WADA Prohibited List, hormone and metabolic modulators, covers anti-oestrogenic substances including SERMs and names clomifene, of which enclomiphene is an isomer. UK Anti-Doping applies strict liability: a prohibited substance in a sample is a violation whatever the intent.
The controlled data concern clomifene. In an open-label study by an anti-doping laboratory, 12 healthy men took clomifene daily for 30 days. The study measured hormone changes and urinary clearance for anti-doping purposes, and zuclomiphene stayed detectable in urine for between 121 and more than 261 days (Miller 2019). No window for isolated enclomiphene was established, and we know of no verified figure. The position is: detectable, window not established. Anyone subject to testing should treat this product as prohibited.
Storage, stability and handling
Keep the bottle sealed in a cool, dry place away from light and heat, and close it promptly after opening, because capsule shells take up moisture. A certificate describes the batch as the laboratory received it, so do not leave capsules on a bench or in sunlight. Do not decant them into unlabelled containers, and keep the batch number with the material. Store out of reach of children and pets. As with any hormonally active research material, wash hands after contact, avoid raising dust if a capsule is opened, and keep opened material away from anyone who is pregnant or breastfeeding. Dispose of unwanted stock through a chemical waste route, not household bins or drains.
What the published research reports
A 2025 meta-analysis pooled randomised controlled trials of SERMs, clomifene and enclomiphene together, in men with functional hypogonadism. Against placebo, total testosterone was on average about 274 ng/dL higher, and luteinising hormone and follicle-stimulating hormone were also raised; heterogeneity between trials was high, and the outcomes were blood hormone levels, not symptoms or long-term health (Hohl 2025). The 2026 British Society for Sexual Medicine statement judged the evidence to come from small, short-term studies with limited data on harms and fertility, and listed headache, hot flushes, nausea, muscle spasms and dizziness as undesirable effects, each below 2 per cent (Foster 2026). A 2026 case report described atrial flutter first documented in a 46-year-old man with earlier heart valve surgery, shortly after his intake was increased; the authors rated the link as possible only, since his existing heart changes could explain it (Tariq 2026). The underlying trials enrolled diagnosed men under medical monitoring. None of this is a claim about the product on this page.
Related compounds and reading
- Enclomiphene, every brand stocked, including Yakka Strength Enclomiphene
- PCT blends, Free Muscle PCT and every Free Muscle product
- Enclomiphene vs clomifene: what the trials report
- What is Janoshik Analytical? and Price per milligram
- How to choose a research compound supplier in the UK
Glossary
- SERM: selective oestrogen receptor modulator, a compound that blocks or activates oestrogen receptors depending on the tissue.
- (E) and (Z) isomers: the two arrangements around a double bond; enclomiphene is (E), or trans, and zuclomiphene is (Z), or cis.
- Citrate salt and free base: the molecule paired with citric acid, and the molecule alone.
- InChIKey: a structure-derived identifier, here GKIRPKYJQBWNGO-OCEACIFDSA-N; its second block reflects the (E) geometry.
- LH and FSH: luteinising hormone and follicle-stimulating hormone, pituitary signals to the testes.
- Secondary hypogonadism: low testosterone from weak pituitary signalling rather than testicular failure.
- Retention time: how long a compound takes to pass through an HPLC column.
Research use only. Enclomiphene is not a licensed medicine or a food supplement, has not been evaluated by the MHRA, EMA or FDA, and is not for human consumption. Adults aged 18 or over only. Nothing on this page is medical, dosing or protocol advice.
References
- Foster J, et al. British Society of Sexual Medicine: Position Statement for the Potential Use of Enclomiphene in the Treatment of Male Hypogonadism. World J Mens Health. 2026;44(3):480-483. PMID: 41714894.
- Hohl A, 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. PMID: 41066380.
- Saffati G, et al. Safety and efficacy of enclomiphene and clomiphene for hypogonadal men. Transl Androl Urol. 2024;13(9):1984-1990. PMID: 39434750.
- Helo S, et al. Serum levels of enclomiphene and zuclomiphene in men with hypogonadism on long-term clomiphene citrate treatment. BJU Int. 2017;119(1):171-176. PMID: 27511863.
- Miller GD, et al. Hypothalamic-Pituitary-Testicular Axis Effects and Urinary Detection Following Clomiphene Administration in Males. J Clin Endocrinol Metab. 2019;104(3):906-914. PMID: 30295816.
- Tariq MN, Abdel Halim AT, Evans JA. Newly Detected Atrial Flutter After Enclomiphene Dose Escalation in a Patient With Prior Mitral Valve Repair and Chronic Immune Thrombocytopenia: A Case Report. Cureus. 2026;18(8):e114562. PMID: 42741668.
