Comparison
Clomiphene vs TB-500
Side-by-side of Clomiphene and TB-500. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Clomiphene
Clomiphene citrate raises LH/FSH and endogenous testosterone in men. SERM TRT alternative, 25 to 50 mg, fertility preserved, visual side effects flagged.
TB-500
TB-500 peptide, a 17-aa thymosin beta-4 fragment. Preclinical tendon and wound healing via actin sequestration. Typical dosage 2 to 5 mg weekly. No human RCTs.
Effects at a glance
Clomiphene
- •SERM that blocks estrogen-receptor negative feedback at the hypothalamus, raising LH and FSH
- •FDA approved 1967 for ovulation induction in anovulatory women at 50 to 100 mg cycle days 5 to 9
- •Off-label in men at 12.5 to 25 mg daily raises endogenous testosterone while preserving fertility
- •Enclomiphene (trans-isomer) is preferred for male use; cleaner PK and less estrogenic side effect burden
- •Visual disturbances occur in ~1 to 2% of users; persistent symptoms warrant immediate cessation
- •Letrozole has displaced clomiphene as first-line ovulation induction in PCOS (Legro 2014)
TB-500
- •17-amino-acid fragment of endogenous Thymosin Beta-4, an actin-sequestering peptide
- •Preclinical models show accelerated tendon, ligament, and dermal wound healing
- •Equine veterinary use for soft-tissue injury is the most documented real-world application
- •Anecdotal human protocols use 2 to 5 mg twice weekly subcutaneously for 4 to 6 weeks
- •WADA banned under S2 (peptide hormones, growth factors) since 2018
- •No completed phase II or III human RCTs as of 2026; long-term safety unestablished
Side-by-side
| Attribute | Clomiphene | TB-500 |
|---|---|---|
| Category | pharmaceutical | peptide |
| Also known as | Clomid, clomiphene citrate, Serophene, enclomiphene | Thymosin Beta-4 fragment, TB4-Frag, Thymosin Beta 4 |
| Half-life (hr) ↗ | 168 | 2 |
| Typical dose (mg) ↗ | 25 | 2.5 |
| Dosing frequency | 5-day pulse cycle days 5 to 9 (women); daily or every other day (men, off-label) | 2x weekly (anecdotal protocols) |
| Routes | oral | subcutaneous, intramuscular |
| Onset (hr) | 6 | - |
| Peak (hr) | 7 | - |
| Molecular weight | 405.96 | 4963.4 |
| Molecular formula | C26H28ClNO | C212H350N56O78S |
| Mechanism | Selective estrogen receptor modulator that antagonizes estrogen at the hypothalamus and pituitary, increasing GnRH and gonadotropin output, which drives gonadal steroidogenesis. | Sequesters G-actin monomers, modulates cell migration and angiogenesis, and upregulates VEGF and myosin transcription. Promotes endothelial differentiation and stem-cell migration to injury sites in preclinical models. |
| Legal status | Prescription only (FDA approved for ovulation induction; off-label in men) | Not FDA approved; research-use-only grey market; banned by WADA |
| WADA status | banned | banned |
| DEA / Rx | Rx only (not a controlled substance) | Not FDA approved; not scheduled; research-chemical status |
| Pregnancy | Category X; contraindicated in pregnancy | Insufficient data |
| CAS | 911-45-5 | 885340-08-9 |
| PubChem CID | 1548953 | 62707662 |
| Wikidata | Q416785 | Q7799921 |
Safety profile
Clomiphene
Common side effects
- hot flushes
- mood changes
- abdominal discomfort
- breast tenderness
- visual disturbances (rare)
- headache
Contraindications
- pregnancy
- active liver disease
- ovarian cysts (not PCOS-related)
- uncontrolled thyroid or adrenal disorder
- abnormal uterine bleeding of undetermined origin
- hormone-sensitive cancer
Interactions
- tamoxifen: competing SERM activity; not used together(moderate)
- ospemifene: competing SERM activity(moderate)
- anastrozole: additive estrogen reduction; sometimes combined in male protocols(minor)
- TRT (exogenous testosterone): TRT suppresses HPT axis that clomiphene targets; do not combine(moderate)
TB-500
Common side effects
- injection-site irritation
- fatigue (anecdotal)
- lethargy in early dosing (anecdotal)
Contraindications
- pregnancy
- active malignancy (theoretical angiogenic concern)
- no established human safety profile
Interactions
- BPC-157: Frequently co-administered in anecdotal healing protocols; no controlled interaction data(minor)
Which Should You Take?
Clomiphene comes out ahead for most readers on the criteria we weight: 2 catalogued goals, prescription-only, oral dosing, with a Tier-A outcome catalogued. TB-500 is the right call when one of the conditionals below applies.
- → If your priority is hormonal optimization, pick Clomiphene.
- → If your priority is fertility, pick Clomiphene.
- → If your priority is post-training recovery, pick TB-500.
- → If your priority is tendon repair, pick TB-500.
Edge case: If you cannot self-administer injections, Clomiphene is the only oral option in this pair.
Default choice: Clomiphene. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for TB-500 only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Clomiphene and TB-500?
Clomiphene and TB-500 differ in category (pharmaceutical vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Clomiphene or TB-500?
Clomiphene half-life is 168 hours; TB-500 half-life is 2 hours.
Can you stack Clomiphene with TB-500?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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