Enclomiphene Capsules UK

Enclomiphene, also written enclomifene and known in development as Androxal or trans-clomiphene, is the (E)-isomer of clomifene citrate. It is a non-steroidal selective oestrogen receptor modulator (SERM) that acts on oestrogen receptors in the hypothalamus and pituitary. This page lists every brand of enclomiphene stocked at Free Muscle, compared on strength per capsule, capsules per pack and whether the batch has been assayed by an independent laboratory. It is sold for laboratory research to adults only.

What is enclomiphene?

Clomifene, the parent compound, is a roughly 60:40 mixture of two geometric isomers. Enclomiphene is the trans (E) isomer. The other, zuclomiphene, has a much longer half-life and is generally described as the more oestrogenic of the two.

The mechanism is antagonism of oestrogen receptors in the hypothalamus. Oestradiol normally feeds back to reduce the release of gonadotropin-releasing hormone, so blocking that signal allows luteinising hormone (LH) and follicle-stimulating hormone (FSH) to rise, which in turn drives testicular testosterone production. This is why enclomiphene was developed as a treatment for secondary hypogonadism in men, rather than as a replacement testosterone.

Enclomiphene citrate went through phase II and phase III clinical trials in the United States under Repros Therapeutics. A new drug application was filed in the United States and withdrawn in 2015 after the FDA raised concerns about the trial endpoints. In the European Union, the EnCyzix application was refused in 2018; the regulator's reasons are given in the research section below. Enclomiphene is available as a prescription medicine in some countries, but it is not licensed by the MHRA in the UK, and it is not an authorised food supplement. Clomifene itself is a prescription-only medicine in the UK.

Labels and certificates may state the citrate salt, the form named in the trials, or the free base, and the figures differ for the same amount of active molecule. Identifiers from PubChem, checked October 2026:

The free base is about 68 per cent of the mass of the citrate (406.0 divided by 598.1).

What the published research reports

Unlike most compounds sold in this category, enclomiphene has controlled human trial data. The findings below are reported neutrally, with their limitations.

• Pharmacokinetic and pharmacodynamic study (2013). A phase II randomised study in 44 men with secondary hypogonadism compared three enclomiphene doses with transdermal testosterone over six weeks. Mean morning testosterone in the highest enclomiphene group reached about 604 ng/dL against about 500 ng/dL with the gel, and only enclomiphene raised LH and FSH, both to above the normal range. Effects persisted for at least a week after stopping. Thyroid, cortisol and lipid values were not significantly changed, but IGF-1 fell in both groups, more so with enclomiphene. The sample was small and the study was short. Wiehle R, et al. Testosterone restoration by enclomiphene citrate in men with secondary hypogonadism: pharmacodynamics and pharmacokinetics. BJU Int. 2013;112(8):1188-1200. PMID: 23875626.
• Phase II trial against topical testosterone (2014). Oral enclomiphene citrate was compared with 1 per cent testosterone gel in men with secondary hypogonadism. Both raised morning serum testosterone to a similar degree. With enclomiphene, oestradiol and LH rose along with testosterone, FSH also rose, and sperm counts were conserved. Wiehle RD, 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. PMID: 25044085.
• Phase III trials in overweight men (2016). Two 16-week phase III studies in overweight men aged 18 to 60 with secondary hypogonadism again found that enclomiphene raised testosterone, LH and FSH while sperm concentration was maintained, and that testosterone gel lowered LH, FSH and sperm concentration. Despite these results the US application was withdrawn after the FDA questioned whether the chosen endpoints showed a clinical benefit to patients. Kim ED, et al. Oral enclomiphene citrate raises testosterone and preserves sperm counts in obese hypogonadal men, unlike topical testosterone: restoration instead of replacement. BJU Int. 2016;117(4):677-685. PMID: 26496621.

In January 2018 the European Medicines Agency's committee, reviewing four main studies in 588 patients, found that testosterone rose but that effects on symptoms, among them libido, impotence, weight gain and bone strength, had not been studied, and it noted a risk of venous thromboembolism, that is, clots forming in the veins. It judged that the benefits did not outweigh the risks.

Across these trials the reported adverse events were generally mild, but the studies were of short duration, in clinically diagnosed patients under medical monitoring, and none of them examined long-term effects, effects in men with normal hormone levels, or effects in women. A SERM acts directly on the endocrine axis, and the trials themselves relied on repeated blood tests. None of the above is a claim about any product on this page.

Brands of enclomiphene we stock

• Free Muscle Enclomiphene 25 mg, 60 capsules. Our own brand, 25 mg per capsule, 60 capsules per pack, giving 1,500 mg of enclomiphene per pack. Every Free Muscle batch is assayed by Janoshik Analytical for identity and purity, and the certificate for the batch you receive is available by email on request. View Free Muscle Enclomiphene 25 mg.
• Yakka Strength Enclomiphene, 60 capsules. A third-party brand in capsule form. The label shown on the listing states 12.5 mg of enclomiphene citrate per capsule and 60 capsules per container, which is 750 mg of the citrate per pack. A batch certificate is shown only where Yakka Strength supplies one for the batch we hold. View Yakka Strength Enclomiphene.

How to compare them

Multiply the strength per capsule by the number of capsules to get total milligrams per pack, then divide the price by that figure for a cost per milligram. Two packs of 60 capsules are not equivalent if one is 12.5 mg and the other 25 mg per capsule, and two equal figures are not equivalent if one refers to the citrate salt and the other to the free base. Where a strength is not printed on the listing, treat the pack as unquantified until you have seen the certificate. Finally, check who tested the batch, what method they used and whether the batch number on the certificate matches the pack.

Batch testing and certificates of analysis

A certificate of analysis (COA) states identity, meaning that the material is enclomiphene and not clomifene or something else, and purity, meaning the proportion of the sample that is enclomiphene, usually by HPLC, along with the laboratory, the method, the batch number, the date and the result. For enclomiphene, identity is an isomer question: enclomiphene and zuclomiphene share one formula and one mass, so the method should separate them, typically by comparing the HPLC retention time with that of an (E)-isomer reference standard. The Free Muscle enclomiphene page goes through each field.

Every Free Muscle batch is tested by Janoshik Analytical, an independent laboratory that we neither own nor control. To request the certificate for your batch, email us with the batch number printed on the pack and we will send it.

A generic PDF with no batch number, no date or no named laboratory is not a batch certificate. It describes one sample at one point in time, not necessarily the material in your hands. For other brands we show a certificate only when the manufacturer has supplied one for the batch we hold. We explain what to look for on our lab testing page.

Where to buy enclomiphene in the UK: how to check a supplier

Whichever shop you buy enclomiphene from, check these five points before you order:

1. A batch number and a certificate for that batch. The pack should carry a batch number, and the seller should be able to show a certificate of analysis for that same batch from a named laboratory, with the test date. Every Free Muscle-brand batch is assayed by Janoshik Analytical, and we send the certificate for your batch on request. For Yakka Strength, a certificate is shown where the brand supplies one for the batch we hold.
2. The strength per capsule and the capsule count. With both figures you can work out the total milligrams in the pack and the price per milligram; the comparison table above does this for every listing here that states both. If a listing does not state one of them, ask the seller before you order.
3. Research-use labelling and an age check. A research compound should be sold for laboratory research use only, not for human consumption, to adults aged 18 or over, with no dosing or usage advice. That is how every listing here is sold.
4. Prices in pounds sterling and tracked UK dispatch. UK delivery from us is free and tracked on every order, with no minimum spend, and usually arrives 2-3 working days after dispatch; orders placed before 2pm Monday to Friday are processed the same working day.
5. A clear returns policy. Unopened items can be returned to us within 30 days.

Brands on this page: Free Muscle and Yakka Strength. The UK supplier checklist and how we test go into more detail.

Legal status in the UK

Enclomiphene is not a licensed medicine in the UK. The MHRA has not granted it a marketing authorisation, and it has never been assessed as a food supplement, so it cannot be sold for consumption. It is supplied by Free Muscle for laboratory research to adults aged 18 or over. Its parent compound clomifene is a prescription-only medicine, and some overseas markets treat enclomiphene the same way.

UK clinical opinion is cautious. A 2026 British Society for Sexual Medicine position statement noted that enclomiphene is unlicensed in the UK and stated that its routine use outside specialist settings is not recommended; where it is prescribed, it advised management by experienced clinicians, ideally within research frameworks (Foster J, et al. World J Mens Health. 2026;44(3):480-483. PMID: 41714894).

For sport, section S4.2 of the 2026 WADA Prohibited List (anti-oestrogenic substances, including SERMs) names clomifene, of which enclomiphene is an isomer, and the class is prohibited at all times, in and out of competition. It is detectable in anti-doping testing. Anyone subject to testing should treat it as prohibited. Our article on why post-cycle therapy is discussed covers the wider background to this class of compound.

Storage and handling

Keep the container tightly sealed in a cool, dry place away from direct light and heat. Do not decant into unlabelled containers, keep the batch number with the material, and handle it in line with good laboratory practice. Keep out of the reach of children and animals.

Delivery and returns

Free Muscle is the trading name of FreeMuscle, a business registered in Andorra, with UK operations and dispatch in Scunthorpe. Every UK order goes out free of charge with tracking, in plain packaging; any order that reaches us by 2pm on a working day is processed on that day, and parcels to the EU take 3 to 7 working days. Returns of unopened items are accepted within 30 days, and every buyer must be 18 or over. Terms: shipping and guarantee.

Related reading

• Enclomiphene vs clomiphene (clomifene): what the trials report
• What is in a PCT blend? Ingredients, evidence and UK status
• How to Read a Certificate of Analysis (COA)
• What Is Janoshik Analytical? Third-Party Testing Explained
• Price per milligram: the only honest way to compare

Related collections: PCT blends, SARMs, Free Muscle and Yakka Strength.

Research compounds sold by Free Muscle are supplied for laboratory research use only and are not for human consumption. They are not authorised as medicines by the MHRA, EMA or FDA, are not food supplements, and are sold only to adults aged 18 or over. Nothing on this page is medical or dosing advice.

Research guides

• Enclomiphene vs clomiphene (clomifene): what the trials report
• What is in a PCT blend? Ingredients, evidence and UK status
• All research guides