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Lexicon
PCT & hormone control

Clomid (Clomiphene)

The classic SERM for PCT - restarts the body's own testosterone production.

1 min read 10 sources

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White tablet bottle with a black TPD label for Clomiphene on a white podium, next to a blue 3D molecule model in a bright lab
Compound approved · since 1967

Summary

At a glance

Sources checked on 26 Oct 2026

Testosterone vs placebo
+274 ng/dl

Meta-analysis of randomised trials, clomiphene and enclomiphene together4

Testosterone in obesity
+11.6 nmol/l

7 studies, 292 men, clomiphene for 1.5 to 4 months5

Mean treatment duration
19 months

86 young men with low testosterone, no major side effects1

In one meta-analysis
1,642 men

19 studies, side effects in under 10%, none serious3

  • Clomiphene is a SERM: it blocks estrogen receptors in the brain. The pituitary then releases more LH and FSH and the testes make more testosterone.104
  • In randomised trials against placebo testosterone rose on clomiphene and enclomiphene by 274 ng/dl on average, LH and FSH by about 4.6 units per litre each.4
  • In overweight men testosterone rose on clomiphene by 11.6 nmol/l on average. Compared with testosterone gel the level was the same, but libido somewhat weaker.56
  • Clomiphene has been approved since 1967 and is used off-label in men. For treatment after anabolic steroids only a pilot study is underway.1038
  • Side effects occurred in less than 10 percent in studies, no serious ones were reported. Everything here is research status, not a recommendation.3
Profile

Updated June 2026

How long does it stay in the body?

Share left after one dose, calculated with a half-life of ~6 days

Half-life ~6 days
After 12 days: 25 %
Day 1, next dose · 89 %Day 6 · 50 %Day 12 · 25 %Day 18 · 12.5 %Day 30 · 3.1 %

Simplified model without an absorption phase, half-life from the TPD lexicon. The lexicon gives 5 to 7 days, we calculate with the middle.

Class
SERM

selective estrogen receptor modulator

Use
Oral

1x per day

Half-life
about 5-7 days
Status
Clinically approved

fertility

Sizes
25 to 50 mg

2 sizes in the shop

Contents 12 sections
  1. At a glance
  2. What is Clomiphene?
  3. How it works
  4. Use and dosing
  5. What the research shows
  6. Research status
  7. Side effects
  8. Storage
  9. Related compounds
  10. FAQ
  11. Glossary
  12. Sources

What is Clomiphene?

Clomiphene (brand name Clomid) is a SERM - a selective estrogen receptor modulator. In the PCT context (post-cycle therapy) it is used to restart the body's own testosterone production after a suppressive anabolic cycle.

This information is for research and educational purposes only. No medical advice.

Comparison

Restarting the axis: routes in the lexicon

What each entry targets, as stated in the TPD lexicon. Tap a card to open its entry.

SERM, mix of both isomers Clomid (Clomiphene) ER Aromatase LH receptor 1 of 3 targets
SERM, pure trans isomer Enclomiphene (Androxal) ER Aromatase LH receptor 1 of 3 targets SERM Tamoxifen (Nolvadex) ER Aromatase LH receptor 1 of 3 targets Aromatase inhibitor Arimidex (Anastrozole) ER Aromatase LH receptor 1 of 3 targets LH analogue HCG ER Aromatase LH receptor 1 of 3 targets

Simplified. SERMs block the estrogen signal in the brain, aromatase inhibitors lower estrogen itself, HCG replaces the LH signal directly at the testes. 74

How it works

Clomiphene blocks the estrogen receptors in the hypothalamus. The body therefore "thinks" estrogen is low and releases more GnRH. That drives LH and FSH up from the pituitary - the two signals that boost testosterone and sperm production in the testes. This restarts the HPTA axis suppressed after a cycle.

Where it acts

Where clomiphene acts

Tap a point or a card. Colour = estrogen receptor, grey = observed.

  1. Hypothalamus and pituitary

    Estrogen signal blocked, LH and FSH rise by about 4.6 units per litre each4

    ERα
  2. Testes

    More own testosterone, +11.6 nmol/l on average in obesity5

    Observed in trials
  3. Muscle

    More lean and muscle mass after 12 weeks against placebo2

    Observed in trials
  4. Blood lipids

    HDL cholesterol fell compared with placebo2

    Observed in trials

Targets in the ChEMBL database10

Compound ChEMBL CHEMBL2355051: one recorded mechanism, Modulator, blocking in the hypothalamus.

Estrogen receptor alpha
Gene
ESR1
UniProt
P03372
ChEMBL
CHEMBL206
Action
Modulator, blocking in the hypothalamus
Glass brain model with blue 3D molecules, below it the glowing stalk of the pituitary above blue gland shapes
Signal from the brain to the pituitary. Symbolic image.

Use and dosing

Dosing

Dosing, titration and syringe

Loading the dosing information …

  • Getting started and stepping up, drawn as a staircase
  • Units on the U-100 syringe for every step
  • How long one vial lasts
Tablet bottle with a black TPD label for Clomiphene next to a glass of water and a few white tablets
Taken orally as a tablet. Symbolic image.

What the research shows

The Katz study (BJU International, 2012) examined clomiphene in young hypogonadal men and showed a clear, stable testosterone rise on 25-50mg, with good tolerability and preserved fertility. That confirms the HPTA reactivation mechanism.

Study results

What the trials measured

Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.

Rise in testosterone in obesity5

Meta-analysis, 7 studies, 292 men, 1.5 to 4 months

Total testosterone5 Change from baseline
Clomiphene +11.6 nmol/l
Enclomiphene +7.5 nmol/l

Values from the abstract (11.56 and 7.50 nmol/l). Without one study in severely obese men clomiphene was at 10.3 nmol/l. There were no unexpected safety findings.

Control hormones vs placebo4

Meta-analysis of randomised trials, mean difference

LH4
Clomiphene or enclomiphene +4.66 IU/l
FSH4
Clomiphene or enclomiphene +4.59 IU/l

Values from the abstract. The analysis pools clomiphene and enclomiphene. Testosterone rose by 274 ng/dl on average against placebo.

Testosterone level compared with testosterone treatment6

Meta-analysis, 11 studies, 1,512 men, mean difference

Vs gel6 8 studies, no clear difference
Clomiphene vs testosterone gel +24 ng/dl
Vs injection6 1 study, 62 men
Clomiphene vs testosterone injection -291 ng/dl

Values from the abstract, rounded (24.29 and -290.50 ng/dl). Across all studies no clear difference. Libido was somewhat weaker on clomiphene than on testosterone.

Petri dish with translucent cell structures and a glowing orange spot under a lab microscope
Studies in men with low testosterone. Symbolic image.

Research status

Where the research stands

ClinicalTrials.gov lists 263 trials with clomiphene, almost all in women trying to conceive. Only trials with clomiphene in men are shown here. Enclomiphene trials belong to its own entry. As of 26 Oct 2026. 9

  1. Preclinical Approved for decades, early data from before the registry era
  2. Phase 1 no registered trial
  3. Phase 2 7 trials, 5 completed, 2 stopped early
  4. Phase 3 1 trial, 1 completed
  5. Approval since 1967
50 participants in phase 3 Approved: ChEMBL lists clomiphene with phase 4 as the highest phase and first approval in 1967. In men it is used off-label.10
Show all 8 phase 2 and 3 trials on a timelineHide timeline 6 completed 0 running 2 stopped early 1 with results
Phase 2
Phase 3

Bar: start to primary endpoint (planned for running trials). Green = completed, blue = progress until 26 Oct 2026, grey = stopped early.

Side effects

  • Visual disturbances: at higher doses rarely flickering or blurred vision - then stop.
  • Mood: some report irritability or low mood (clomiphene has estrogenic effects in the brain).
  • Hot flashes, nausea: dose-dependent.

Storage

Store dry and protected from light. Out of reach of children.

Three white tablet bottles and a folded light blue towel on a white shelf
Dry and protected from light. Symbolic image.
Level · Clomid (Clomiphene)

How the level builds up

One dose per day: each dose adds to what is left of the previous one.

Lexicon: Oral, 1x per day
Peak 9.17×Trough 8.17×
Day 23 · 24. dose
8.59× of the first dose
Plateau
from Day 25

95 % of the plateau after dose 26

Peak
9.17×

of the first dose

Trough
8.17×

before the next dose

Simplified model, values relative to the first dose, no dosing information. Dashed: the first dose alone, green: the plateau.

Related

Related compounds

Same receptors or a different path: all in the TPD lexicon.

Clomid (Clomiphene)
Enclomiphene (Androxal) Pure trans isomer of clomiphene Tamoxifen (Nolvadex) Also a SERM Arimidex (Anastrozole) Different path: lowers estrogen, compared directly with clomiphene Aromasin (Exemestane) Different path: aromatase inhibitor Letrozole (Femara) Different path: aromatase inhibitor HCG Different path: acts directly on the testes

FAQ

Common questions about Clomid (Clomiphene)

Short answers, each backed by the sources below.

How does clomiphene work in men?

It blocks estrogen receptors in the brain. The brain then senses too little estrogen, the pituitary releases more LH and FSH and the testes make more of their own testosterone. Against placebo LH and FSH rose by about 4.6 units per litre each.104

Is clomiphene approved?

Yes, ChEMBL lists clomiphene with first approval in 1967, according to the entry for fertility treatment. In men with low testosterone it is used off-label.103

How much does testosterone rise?

In randomised trials against placebo by 274 ng/dl on average (clomiphene and enclomiphene together). In overweight men it rose by 11.6 nmol/l on clomiphene. In a long-term follow-up of 19 months on average testosterone and control hormones were higher during treatment.451

Clomiphene or testosterone?

Compared with testosterone gel the testosterone level was the same, testosterone injections reached higher levels in one study. Libido was somewhat weaker on clomiphene. The advantage: clomiphene stimulates own production instead of slowing it, which matters for fertility.63

Are there studies after anabolic steroids?

So far only a Norwegian pilot study whose plan has been published: men stopping anabolic steroids receive 16 weeks of clomiphene, initially with testosterone gel and HCG if needed. According to the authors there is no consensus on whether hormone treatment after stopping is useful.8

Which side effects are known?

In a meta-analysis with 1,642 men side effects occurred in less than 10 percent, no serious ones were reported. In a placebo study HDL cholesterol fell. The entry also names visual disturbances and mood swings.32

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

FSH
Follicle-stimulating hormone. In men important for sperm production.
GnRH
Gonadotropin-releasing hormone from the hypothalamus. It releases LH and FSH.
HPTA
Hypothalamic-pituitary-testicular axis, the control loop of own testosterone production.
Hypogonadism
Too little testosterone because the testes or the control in the brain do not deliver enough.
Hypothalamus
Control centre in the brain that stimulates the pituitary via GnRH.
LH
Luteinising hormone from the pituitary. It stimulates testosterone production in the testes.
Off-label
Use of a medicine outside its approved indication.
PCT
Post-cycle therapy: phase after anabolic steroids in which own hormone production is meant to restart.
Pituitary
Gland at the base of the brain that releases LH and FSH into the blood.
SERM
Selective estrogen receptor modulator: blocks estrogen receptors in some tissues and activates them in others.

Evidence

Sources

Show all 10 sourcesHide sources 8 Studies1 Trial registry1 Database checked 26 Oct 2026

Studies

  1. Clomiphene in young men with low testosterone, long-term follow-up

    Katz et al., BJU International, 2012

    DOI 10.1111/j.1464-410X.2011.10702.x PMID 22044663
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  2. Clomiphene in obesity and low testosterone, against placebo

    Soares et al., International Journal of Obesity, 2018

    DOI 10.1038/s41366-018-0105-2 PMID 29777228
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  3. Clomiphene in men, review and meta-analysis

    Huijben et al., Andrology, 2022

    DOI 10.1111/andr.13146 PMID 34933414
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  4. Clomiphene and enclomiphene, meta-analysis of randomised trials

    Hohl et al., Archives of Endocrinology and Metabolism, 2025

    DOI 10.20945/2359-4292-2025-0093 PMID 41066380
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  5. SERMs in overweight men, meta-analysis

    Tienforti et al., Andrology, 2023

    DOI 10.1111/andr.13373 PMID 36604313
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  6. Clomiphene vs testosterone, meta-analysis

    Constantinou et al., European Journal of Clinical Pharmacology, 2026

    DOI 10.1007/s00228-026-04134-3 PMID 42435198
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  7. Clomiphene vs anastrozole, randomised

    Helo et al., The Journal of Sexual Medicine, 2015

    DOI 10.1111/jsm.12944 PMID 26176805
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  8. Pilot study plan: clomiphene after stopping anabolic steroids

    Havnes et al., MethodsX, 2024

    DOI 10.1016/j.mex.2024.102810 PMID 39022178
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed

Trial registry

  1. Clomiphene on ClinicalTrials.gov

    ClinicalTrials.gov, U.S. National Library of Medicine

    Checked 26 Oct 2026 via ClinicalTrials.gov API v2

Database

  1. Clomiphene in ChEMBL (approval and target)

    ChEMBL, EMBL-EBI (CHEMBL2355051)

    Checked 26 Oct 2026 via ChEMBL API

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Clomid (Clomiphene) in the catalog

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