Comparison
Thymosin Alpha-1 vs Tirzepatide
Side-by-side of Thymosin Alpha-1 and Tirzepatide. 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.
Thymosin Alpha-1
Thymosin alpha-1 peptide (Zadaxin, thymalfasin): 28-amino-acid TA1 immunomodulator. Dosing, T-cell effects, hepatitis B and HCV adjunct evidence.
Tirzepatide
Tirzepatide for weight loss: dual GIP/GLP-1 agonist sold as Mounjaro and Zepbound. SURMOUNT-1 showed 22.5% mean body-weight loss at 15 mg over 72 weeks.
Effects at a glance
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
Tirzepatide
- •Dual GIP plus GLP-1 receptor agonist with a ~5-day half-life supporting once-weekly subcutaneous dosing
- •SURMOUNT-1 reported ~22.5% mean body-weight loss at 15 mg over 72 weeks versus 2.4% on placebo
- •Lowers HbA1c by ~1.9 to 2.6 percentage points in type 2 diabetes across SURPASS trials
- •Outperformed semaglutide 1.0 mg head-to-head on weight loss and HbA1c in SURPASS-2
- •GI effects (nausea, diarrhea, vomiting) drive most discontinuations and ease with slow titration
- •Lean-mass loss observed in body-composition substudies; resistance training and protein intake mitigate this
Side-by-side
| Attribute | Thymosin Alpha-1 | Tirzepatide |
|---|---|---|
| Category | peptide | pharmaceutical |
| Also known as | Talpha1, Ta1, Zadaxin, Thymalfasin | Mounjaro, Zepbound, LY3298176 |
| Half-life (hr) ↗ | 2 | 120 |
| Typical dose (mg) ↗ | 1.6 | 10 |
| Dosing frequency | 2x weekly | weekly |
| Routes | subcutaneous, intramuscular | subcutaneous |
| Onset (hr) | 24 | 24 |
| Peak (hr) | 168 | 72 |
| Molecular weight | 3108.32 | 4813.45 |
| Molecular formula | C129H215N33O55 | C225H348N48O68 |
| Mechanism | 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. | Synthetic 39-amino-acid peptide that activates both GIP and GLP-1 receptors. Potentiates glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and acts on hypothalamic and brainstem satiety circuits. |
| Legal status | 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 | Prescription only; FDA-approved 2022 (T2DM, Mounjaro) and 2023 (chronic weight management, Zepbound) |
| WADA status | unknown | allowed |
| DEA / Rx | Rx only via international approval or US compounding (no controlled-substance schedule) | Rx only (not a controlled substance) |
| Pregnancy | Not recommended; insufficient data | Not recommended; discontinue 2 months before planned pregnancy |
| CAS | 62304-98-7 | 2023788-19-2 |
| PubChem CID | 16130571 | 156588324 |
| Wikidata | Q913854 | Q105099794 |
Safety profile
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)
Tirzepatide
Common side effects
- nausea
- diarrhea
- vomiting
- constipation
- decreased appetite
- injection-site reactions
- fatigue
- abdominal pain
Contraindications
- personal or family history of medullary thyroid carcinoma
- multiple endocrine neoplasia type 2
- pregnancy
- history of pancreatitis (use caution)
- severe gastroparesis
Interactions
- insulin: additive hypoglycemia risk; insulin dose typically reduced(major)
- sulfonylureas (glipizide, glyburide): hypoglycemia risk, sulfonylurea dose often reduced(major)
- oral medications (general): delayed gastric emptying can alter absorption kinetics(moderate)
- oral contraceptives: reduced exposure after first dose; backup contraception recommended for 4 weeks after initiation and each dose escalation(moderate)
- warfarin: monitor INR due to altered absorption(moderate)
Which Should You Take?
Thymosin Alpha-1 and Tirzepatide 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 immune support, pick Thymosin Alpha-1.
- → If your priority is post-training recovery, pick Thymosin Alpha-1.
- → If your priority is metabolic health and glucose control, pick Tirzepatide.
- → If your priority is fat loss, pick Tirzepatide.
Edge case: Half-lives differ materially (Thymosin Alpha-1 ~2 hr vs Tirzepatide ~120 hr). Tirzepatide reaches steady state faster; Thymosin Alpha-1 is easier to dial in if tolerability is uncertain.
Default choice: either is defensible. Thymosin Alpha-1 edges out on goal breadth + legal accessibility; Tirzepatide 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 Thymosin Alpha-1 and Tirzepatide?
Thymosin Alpha-1 and Tirzepatide differ in category (peptide vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Thymosin Alpha-1 or Tirzepatide?
Thymosin Alpha-1 half-life is 2 hours; Tirzepatide half-life is 120 hours.
Can you stack Thymosin Alpha-1 with Tirzepatide?
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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