Comparison
Clomiphene vs Thymosin Alpha-1
Side-by-side of Clomiphene and Thymosin Alpha-1. 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.
Thymosin Alpha-1
Thymosin alpha-1 peptide (Zadaxin, thymalfasin): 28-amino-acid TA1 immunomodulator. Dosing, T-cell effects, hepatitis B and HCV adjunct evidence.
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)
Thymosin Alpha-1
- •28-amino-acid synthetic peptide identical to thymic-derived immunomodulator
- •Approved in over 35 countries as Zadaxin for hepatitis B, hepatitis C adjunct, and immune support
- •Not FDA approved in US; compounded by 503A/503B pharmacies for off-label immune support
- •Modulates T-cell maturation, NK activity, and Th1 polarization in immunocompromised states
- •Standard label dose: 1.6 mg subcutaneously twice weekly
- •Cleanest safety profile in the peptide class with hundreds of regulated trials behind it
Side-by-side
| Attribute | Clomiphene | Thymosin Alpha-1 |
|---|---|---|
| Category | pharmaceutical | peptide |
| Also known as | Clomid, clomiphene citrate, Serophene, enclomiphene | Talpha1, Ta1, Zadaxin, Thymalfasin |
| Half-life (hr) ↗ | 168 | 2 |
| Typical dose (mg) ↗ | 25 | 1.6 |
| Dosing frequency | 5-day pulse cycle days 5 to 9 (women); daily or every other day (men, off-label) | 2x weekly |
| Routes | oral | subcutaneous, intramuscular |
| Onset (hr) | 6 | 24 |
| Peak (hr) | 7 | 168 |
| Molecular weight | 405.96 | 3108.32 |
| Molecular formula | C26H28ClNO | C129H215N33O55 |
| Mechanism | Selective estrogen receptor modulator that antagonizes estrogen at the hypothalamus and pituitary, increasing GnRH and gonadotropin output, which drives gonadal steroidogenesis. | Synthetic peptide modulator of innate and adaptive immunity. Promotes T-cell maturation and CD4/CD8 production, modulates Th1/Th2 balance, stimulates NK cell activity, and modulates TLR2/TLR9 signaling in dendritic cells. |
| Legal status | Prescription only (FDA approved for ovulation induction; off-label in men) | Approved in 35+ countries as Zadaxin (hepatitis B, hepatitis C adjunct, immune support); not FDA approved in US; compounded by 503A/503B pharmacies for off-label use; not on WADA Prohibited List |
| WADA status | banned | unknown |
| DEA / Rx | Rx only (not a controlled substance) | Rx only via international approval or US compounding (no controlled-substance schedule) |
| Pregnancy | Category X; contraindicated in pregnancy | Not recommended; insufficient data |
| CAS | 911-45-5 | 62304-98-7 |
| PubChem CID | 1548953 | 16130571 |
| Wikidata | Q416785 | Q913854 |
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)
Thymosin Alpha-1
Common side effects
- mild injection-site irritation (rare)
- transient mild fatigue (rare)
- occasional headache (rare)
Contraindications
- pregnancy
- lactation
- active organ transplant rejection therapy
- systemic immunosuppression for autoimmune disease (relative)
- severe active autoimmune disease (caution)
Interactions
- interferon-alpha: additive immune effect; used clinically in approved combination protocols(minor)
- calcineurin inhibitors (cyclosporine, tacrolimus): theoretical destabilization of immunosuppression; avoid(major)
- antimetabolites (azathioprine, mycophenolate): theoretical destabilization of immunosuppression; avoid(major)
- vaccine administration: may augment vaccine response in elderly or immunocompromised; coordinate with clinician(minor)
Which Should You Take?
Clomiphene and Thymosin Alpha-1 score evenly on the criteria we weight (goal breadth, legal accessibility, evidence depth). The conditionals below should drive the decision more than any aggregate score.
- → If your priority is hormonal optimization, pick Clomiphene.
- → If your priority is fertility, pick Clomiphene.
- → If your priority is immune support, pick Thymosin Alpha-1.
- → If your priority is post-training recovery, pick Thymosin Alpha-1.
Edge case: If you cannot self-administer injections, Clomiphene is the only oral option in this pair.
Default choice: either is defensible. Clomiphene edges out on goal breadth + legal accessibility; Thymosin Alpha-1 is the right call if your priority sits in the goals listed 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 Thymosin Alpha-1?
Clomiphene and Thymosin Alpha-1 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 Thymosin Alpha-1?
Clomiphene half-life is 168 hours; Thymosin Alpha-1 half-life is 2 hours.
Can you stack Clomiphene with Thymosin Alpha-1?
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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