|All Peptides

Read the full guides

Enclomiphene

Last reviewed: August 27, 2026 by The Peptide Catalog Team

An oral SERM that raises the body's own testosterone by lifting LH and FSH — studied as a fertility-sparing alternative to testosterone therapy. Enclomiphene is the trans-isomer of clomiphene and a selective estrogen receptor modulator (SERM) investigated for raising endogenous testosterone by stimulating the hypothalamic-pituitary-gonadal axis. It reached Phase 3 trials for secondary hypogonadism but is not FDA-approved; vendors sell it as an oral research compound.

Overview

Enclomiphene Results Timeline

Progression
1
Week 1-2
Physical Changes
Little outward change; the axis begins responding to blocked estrogen feedback
Performance & Recovery
LH and FSH rise; total testosterone starts climbing (Wiehle 2013)
Other Benefits
Effects are read on bloodwork, not sensation, at this stage
2
Week 3-6
Physical Changes
Total testosterone moving toward the normal range on daily oral dosing
Performance & Recovery
Gonadotropin-driven response measurable on labs
Other Benefits
Some users self-report energy and libido changes; community-reported, not trial-measured
3
Month 2-3
Physical Changes
Testosterone sustained near the comparator level of testosterone gel (Kim 2016)
Performance & Recovery
Sperm counts preserved or rising, unlike on topical testosterone
Other Benefits
The restore-not-replace pattern is established over this window
4
3-6+ Months
Physical Changes
Testosterone maintained while spermatogenesis continues
Performance & Recovery
Sperm concentration held up in Phase 3 vs 33-57% declines on gel (Kim 2016)
Other Benefits
Investigational and unapproved; trial durations ran 12-24 weeks

Timeline is illustrative and non-guaranteed. Outcomes vary and are commonly discussed alongside training, nutrition, sleep, and cycling practices.

How It WorksSelective Estrogen Receptor Modulator (SERM) — trans-Clomiphene

Target → Signal → Effect → Outcomes

1
Target

Estrogen Receptors at the Hypothalamus & Pituitary

Enclomiphene is the trans-isomer of clomiphene citrate. It acts as an estrogen-receptor antagonist at the hypothalamus and pituitary — the sites where circulating estrogen (much of it aromatized from testosterone) normally signals the brain to slow down. By occupying those receptors, enclomiphene stops the brain from "seeing" that estrogen feedback.

2
Cellular Signal

Released Feedback → More GnRH → LH & FSH

With negative feedback blocked, the hypothalamus increases gonadotropin-releasing hormone (GnRH), and the pituitary responds by releasing more luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Pharmacodynamic work (Wiehle et al., 2013) documented both gonadotropins rising within two weeks of oral dosing.

3
Systemic Effect

Endogenous Testosterone Up, Spermatogenesis Preserved

Higher LH drives the testicular Leydig cells to make more of the body's own testosterone, while FSH supports Sertoli-cell function and sperm production. Because the testosterone is produced inside the testis rather than supplied from outside, intratesticular testosterone and spermatogenesis are preserved — the opposite of what exogenous testosterone does (Kaminetsky 2013, Kim 2016).

4
What You Notice

Bloodwork Shifts Before Sensation

The earliest signs are on labs — rising LH, FSH, and total testosterone — rather than felt effects. Trial subjects reached testosterone levels comparable to testosterone gel over weeks of daily oral dosing. Any energy or libido changes are self-reported by community sources rather than trial endpoints.

What Makes This Peptide Different

Enclomiphene is unusual because it raises testosterone by lifting the body's own signal, not replacing the hormone. Where HCG mimics LH directly at the testis, enclomiphene works one level higher — at the brain — and does so as an oral capsule rather than an injection. It is the isolated trans-isomer of clomiphene, developed to drive the gonadotropin response without the longer-lasting, more estrogenic zuclomiphene fraction that accumulates on clomiphene.

Enclomiphene Vendors

COA

Swiss Chems

Score
10/10
Price
$79.95
Amount
750mg
Cost/mg
$0.11/mg
Ships Worldwide
View at Swiss Chems
Dosing ProtocolTestosterone Support / Fertility-Sparing (Secondary Hypogonadism)

Educational reference only. Individual responses vary. Consult healthcare provider before use.

Vial Size
12.5 mg capsules (60-capsule bottle, oral)
Reconstitution
N/A (oral capsules — no bacteriostatic water)
Dose
12.5-25 mg (trial dose range)
Timing
AM, once daily
Frequency
Daily
Duration
12-24 weeks (clinical trial durations)
Protocol Notes
Selective estrogen receptor modulator (trans-clomiphene isomer), not a peptide. Blocks estrogen feedback at the hypothalamus/pituitary → raises LH, FSH, and endogenous testosterone while preserving sperm production (Kaminetsky 2013, Kim 2016). Completed Phase 3 as an oral alternative to testosterone therapy but was never FDA-approved; research-grade material is labeled not for human consumption.

Why This Dosing Protocol

Why once-daily oral? Enclomiphene is orally active with pharmacokinetics suited to once-daily dosing (Wiehle et al., 2013), and every trial administered it that way. Trial doses clustered around 12.5-25 mg daily across the Phase 2 and Phase 3 program.

Why the isomer matters. Clomiphene citrate is roughly 62% zuclomiphene and 38% enclomiphene. Isolating the trans-isomer was intended to deliver the estrogen-antagonist, gonadotropin-raising effect while avoiding the accumulating zuclomiphene fraction. Enclomiphene completed Phase 3 for secondary hypogonadism but was never FDA-approved.

Storage & Handling

Storage at a glance

Proper storage temperatures, shelf life, reconstitution best practices, and travel tips for lyophilized and reconstituted peptides.

Powder: Freezer
1+ year at -20°C
Reconstituted: Fridge
4 weeks max at 2-8°C
View Complete Storage Guide

Handling specifics

Educational overview on storage, labeling, and traceability considerations for lab environments. Consult primary literature and vendor documentation for specifics.

Powder storage (very stable)
  • Freezer (-20°C): 1+ year
  • Refrigerator (2-8°C): 1-3 months
  • Room temperature: 2-3 weeks (emergency only)
Reconstituted storage (fragile)
  • MUST refrigerate at 2-8°C
  • 4-week maximum shelf life
  • NEVER freeze after reconstitution
  • Use bacteriostatic water for multi-dose

FAQ

What is enclomiphene and how does it work?

Enclomiphene is the trans-isomer of clomiphene citrate — a selective estrogen receptor modulator (SERM), not a peptide. It blocks estrogen receptors at the hypothalamus and pituitary, removing the negative feedback that normally holds gonadotropins down. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) rise, and the testes are stimulated to produce more of the body's own testosterone while keeping sperm production running.

How is enclomiphene different from testosterone therapy?

Testosterone therapy adds hormone from outside and suppresses the body's own LH, which shuts down intratesticular testosterone and can impair fertility. Enclomiphene works in the opposite direction — it raises the upstream signal so the testes make more endogenous testosterone. In two parallel Phase 3 studies (Kim et al., 2016), enclomiphene raised testosterone comparably to testosterone gel while preserving sperm counts the gel reduced.

What is the difference between enclomiphene and clomiphene?

Clomiphene citrate is a mixture of two isomers: zuclomiphene (the longer-lasting, more estrogenic cis-isomer) and enclomiphene (the trans-isomer, an estrogen-receptor antagonist that clears faster). Pharmacokinetic work (Wiehle et al., 2013) describes enclomiphene as the component that drives the gonadotropin and testosterone response, without the accumulating zuclomiphene fraction.

Is enclomiphene FDA-approved?

No. Enclomiphene completed Phase 3 trials for secondary hypogonadism but was never FDA-approved, so no finished pharmaceutical product exists. Research-grade material sold by vendors is labeled for laboratory use only and not for human consumption. This page reports what published trials documented, not medical advice.

How long does reconstituted peptide last?

Once mixed with bacteriostatic water, peptides remain stable for up to 4 weeks when refrigerated at 2-8°C (36-46°F). Unopened powder can last 1+ year in the freezer. Get our complete Storage & Travel Guide.

Is this peptide legal to purchase?

Peptides sold "for research purposes only" are legal to purchase in the US, but are not FDA-approved for human use outside of specific medical applications. Always consult a healthcare provider before use.

New to peptides?

Take our Peptide Match tool to find the best peptide for your goals. You can also read our Complete Guide to Peptides to learn the basics.

Enclomiphene Research Articles

Disclosure: we may earn affiliate commission from qualifying purchases. Educational information only — not medical advice.