🔑 Key Takeaways
- Retatrutide is only available as a research peptide — no FDA-approved version exists yet (still in Phase 3 trials)
- Ascension Peptides carries it as R-10 (10mg, $120) and R-30 (30mg, $200)
- R-30 is better value: $6.67/mg vs $12/mg for R-10
- Always verify third-party COA before buying — retatrutide is complex to synthesize and counterfeits exist
- Standard starting dose: 2mg/week subcutaneous — R-30 lasts 15 weeks at this dose
- No prescription needed for research peptide form
~24%Avg weight loss in Phase 2 trials
$200R-30 (30mg) at Ascension
$6.67/mgBest price point (R-30)
≥98%Purity to require
What Is Retatrutide?
Retatrutide (LY3437943) is a triple GLP-1/GIP/glucagon agonist developed by Eli Lilly. It's still in Phase 3 clinical trials, making it the most potent weight loss peptide available that has no FDA-approved prescription version yet. Phase 2 trials showed average weight loss of ~24% at 48 weeks — higher than semaglutide (~15%) or tirzepatide (~22%). The only way to access it currently is via research peptide vendors.
Where to Buy Retatrutide — Our Top Pick
Ascension Peptides is our primary recommendation:
- Carries R-10 (10mg, $120) and R-30 (30mg, $200)
- US-based manufacturing
- Third-party COA on every batch — HPLC purity ≥98%
- Mass spectrometry verification (critical for a complex triple agonist)
- Discreet US domestic shipping
→ Buy R-30 at Ascension Peptides
R-10 vs R-30 — Which Should You Buy?
| R-10 (10mg) | R-30 (30mg) | |
|---|---|---|
| Price | $120 | $200 |
| Cost per mg | $12/mg | $6.67/mg |
| Duration at 2mg/week | ~5 weeks | ~15 weeks |
| Duration at 4mg/week | ~2.5 weeks | ~7.5 weeks |
| Best for | Testing/first vial | Ongoing use, better value |
| Reconstitution | 1–2mL BAC water | 3–6mL BAC water |
Verdict: R-10 is good for a first purchase to verify quality. R-30 is significantly better value for ongoing use. At 2mg/week, R-30 lasts ~15 weeks — over 3 months per vial.
What to Look for When Buying Retatrutide
Non-negotiable criteria:
- Third-party COA — not just "testing available on request." Must be batch-specific, from an independent lab.
- HPLC purity ≥98% — retatrutide is a large, complex peptide. Synthesis errors are common. Substandard purity means weaker or unpredictable effects.
- Mass spectrometry data — confirms the amino acid sequence is correct. Critical for a triple agonist where the sequence determines which receptors it binds.
- US-based or US-warehoused — avoids customs seizure, heat degradation in transit, longer delays.
- Transparent pricing — vendors who hide pricing until checkout or add surprise fees are a red flag.
Red Flags to Avoid
- ❌ No COA or COA only "available on request"
- ❌ Purity not listed, or listed as "≥95%" without HPLC documentation
- ❌ Dramatically underpriced (R-30 for $60 = almost certainly underdosed)
- ❌ Ships from overseas with no US warehouse
- ❌ No mass spectrometry data (especially important for retatrutide)
- ❌ Generic product photos with no lot number information
Retatrutide Pricing Reference (2026)
| Vial | Expected Price | Red Flag Price |
|---|---|---|
| Retatrutide 10mg (R-10) | $100–140 | Under $50 |
| Retatrutide 30mg (R-30) | $175–220 | Under $100 |
Reconstituting Retatrutide After Purchase
- Add BAC water to the vial slowly (down the inside wall, never directly onto powder)
- Recommended: 2mL per 10mg vial = 5mg/mL. 3mL per 30mg vial = 10mg/mL.
- Full guide at: /blog/retatrutide-reconstitution-guide
- Calculator: Reconstitution Calculator
- Store refrigerated, use within 28 days
Retatrutide Dosage After Purchase
- Starting dose: 0.5–2mg per week (once weekly subcutaneous injection)
- Titrate up gradually to manage GI side effects
- Most effective protocols reach 4–8mg/week over time
- Full dosage chart: /blog/retatrutide-dosage-chart
Is retatrutide legal to buy?
Yes — as a research peptide, retatrutide is legal to purchase in the US. There is no FDA-approved prescription version yet (it's in Phase 3 trials), so it's sold by research peptide vendors without a prescription.
What's the difference between R-10 and R-30?
R-10 is a 10mg vial ($120) and R-30 is a 30mg vial ($200) — both are Ascension Peptides' product codes for retatrutide. R-30 offers significantly better value at $6.67/mg vs $12/mg.
How long does a retatrutide vial last?
R-30 at 2mg/week lasts approximately 15 weeks. At 4mg/week, about 7–8 weeks. At 8mg/week, about 3–4 weeks.
Where is the cheapest retatrutide?
Ascension R-30 at $200/30mg ($6.67/mg) is among the best value from a verified vendor. Be cautious of dramatically cheaper options — purity is critical with retatrutide.
Do I need a prescription to buy retatrutide?
No — research peptide forms don't require a prescription. The future FDA-approved drug (if approved) will require one, but the research peptide form currently does not.
How do I know if retatrutide is real?
Request the COA: HPLC purity ≥98%, mass spectrometry confirming the molecular weight matches retatrutide (MW ~4556 Da), and a batch number that matches your vial label.
Can I buy retatrutide from Ascension Peptides?
Yes. R-10 (10mg, $120) and R-30 (30mg, $200) are available at ascensionpeptides.com with third-party COA.
The information in this article is for educational purposes only and does not constitute medical advice. Always consult a healthcare professional before starting any new supplement or compound. Results vary by individual.