On this page
Typically prepared by a compounding pharmacy under the direction of a licensed healthcare professional — not an FDA-approved finished product in this form.
Overview
Product & regulatory status
Investigational/compounded in US practice; European regulators refused EnCyzix authorization in 2018.
Feedback signalling
Estrogen-receptor modulation increases pituitary LH and FSH signalling, which can raise endogenous testosterone when the reproductive axis can respond. [1]
What the evidence shows
Hormones and sperm endpoints
Two phase III trials in overweight men with secondary hypogonadism found increased testosterone with enclomiphene and testosterone gel. Enclomiphene maintained sperm concentrations, while gel reduced them. Follow-up was short and the endpoints were hormone/semen measurements. [1]
Why the regulatory decision matters
EMA reviewed four main studies involving 588 patients. It found that higher testosterone had not established improvements in symptoms such as libido or impotence, and that thromboembolism concerns prevented a favorable benefit-risk conclusion. [2]
What remains unknown
Pregnancy, live birth, durable symptom benefit and long-term cardiovascular safety are not established by a normal testosterone or sperm concentration. A fertility-preserving claim needs the exact outcome specified.
Safety
Blood-clot concern
EMA identified venous thromboembolism as a risk in its benefit-risk assessment; “stimulates your own production” does not mean risk-free. [2]
Product equivalence
A compounded preparation does not receive FDA premarket approval and should not be assumed identical to a trial product. [3]
What was tested
The phase III evidence concerns defined oral trial products, not every compounded tablet, capsule or combination. [1]
Understanding product quality
Compounded drugs are not FDA-approved finished products. Poor preparation can cause contamination or incorrect strength. A catalog entry or a research paper is not a quality assessment of your product. [4]
When to seek urgent help
Severe allergic symptoms such as trouble breathing, throat or tongue swelling, or fainting need immediate help. Call 911 or your local emergency number. This is general emergency information, not a complete list of risks for this compound. [5]
A starting point for discussion
This is not a complete list of adverse effects or interactions. Your health history, other medicines, and the exact formulation matter. Missing safety data is not evidence of safety.
Common questions
Is enclomiphene simply Clomid?
No. Clomiphene contains more than one isomer; evidence and product identity should be checked separately.
Does maintaining sperm concentration guarantee fertility?
No. Semen concentration is one part of fertility assessment, not a pregnancy or live-birth outcome.
Questions for your clinician
Does the evidence match my condition and this exact product? What risks or interactions matter for me? How would we assess whether it is helping?
Sources
- Kim et al.: enclomiphene phase III studiesBJU International, 2016; two randomized trials in overweight men with secondary hypogonadism; hormone and sperm endpoints.
- EMA: EnCyzix authorization refusal2018 regulatory decision; testosterone/sperm endpoints did not establish symptom benefit, and venous-thromboembolism risk remained a concern.
- FDA: compounding questions and answersFDA explanation of compounded-drug approval and quality differences; accessed September 9, 2026.
- Compounding and the FDA: Questions and AnswersFDA · product quality and regulation
- AnaphylaxisMedlinePlus · recognizing an emergency
Educational information, not a recommendation to use a compound. Kairo does not give dosing advice. Review decisions with a licensed healthcare professional.