Metabolic / Weight Loss · 5mg × 10 vials
appetite goes down, food sits longer, and the metabolism actually speeds up - which is why outcomes blow past semaglutide and tirzepatide in head-to-head reads.
Retatrutide (LY3437943) is a once-weekly injectable peptide that hits three metabolic receptors at once: GLP-1 (the "Ozempic pathway", appetite suppression + slowed gastric emptying), GIP (the "Mounjaro/tirz pathway", amplifies insulin response and is thought to soften GLP-1 nausea), and the glucagon receptor (which the older GLP-1s avoided - it drives the liver to burn fat for energy and bumps total energy expenditure). The glucagon arm is what makes reta different from semaglutide and tirzepatide: instead of just eating less, the body also burns more. Receptor binding studies show retatrutide is most potent at GIP (EC50 ~0.06 nM) with balanced activity at GLP-1 and glucagon, and structural work in Cell Discovery (2024) shows it engages all three GPCRs simultaneously via a conserved core sequence built from the GIP and glucagon backbones. In plain language: appetite goes down, food sits longer, and the metabolism actually speeds up - which is why outcomes blow past semaglutide and tirzepatide in head-to-head reads.
Typical dose ranges by experience level - educational reference. Message us and we tailor it to you.
Standard Phase 2 protocol started at 2 mg. Community consensus on r/Peptides and the peptide forums is the trial schedule is too aggressive for first-timers - starting at 500 mcg cuts nausea/vomiting dramatically and is what almost every PP customer is run on. Reconstitute 5 mg vial with 2 ml BAC = 2.5 mg/ml, so 0.5 mg = 0.20 ml = 20 IU on a U-100 syringe. Inject subQ into abdomen or outer thigh, rotate sites. Morning injection on a low-fat day reduces nausea per community reports.
NEJM Phase 2 at 4 mg averaged 17.1% body weight loss at 48 weeks, 8 mg averaged 22.8%. This is where the body composition reads start matching bariatric surgery outcomes. Heart rate creep of ~6-10 bpm is the standard signal at this band - check resting HR weekly, hold dose if it climbs >15 bpm above baseline.
TRIUMPH-1 Phase 3 (2026) at 12 mg averaged 28.3% body weight loss at 80 weeks, with 45% of participants hitting ≥30% loss. Discontinuation rate at 12 mg was 11.3% (vs 4.9% placebo) - most due to GI sides during titration, not at maintenance. Dysesthesia (burning/sunburn-like skin sensation) hit 20.9% at 12 mg, a signal that emerged only at top doses. Advanced users running 12 mg typically pair with a maintenance taper plan from the start.
Straight talk - what people actually report, and what the studies measured.
Peer-reviewed studies and clinical guidelines - tap any to read the source.
pivotal efficacy/safety, 338 pts, 48 weeks, up to 24.2% weight loss at 12 mg
Read study ↗PubMedRetatrutide-A Game Changer in Obesity Pharmacotherapy, PMC12190491review of mechanism, MASLD data (89-93% achieved liver fat <5%), kidney outcomes
Read study ↗PubMedStructural insights into triple agonism, Cell Discovery 2024 (PMC11255275)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11255275/) - receptor pharmacology, why all three GPCRs engage simultaneously
Read study ↗PubMedMASLD Phase 2a trial, Nature Medicine 2024fatty liver outcomes
Read study ↗PubMedHeart rate meta-analysis of GLP-1 RAs (PMC12918571)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12918571/) - +3.46 bpm mean increase signal
Read study ↗Clinical guidelinesEli Lilly TRIUMPH-1 Phase 3 press release, 202628.3% loss at 80 wk, 45% hit ≥30% loss
Read study ↗Aggregated sentiment from public forums & socials - real-world reports, not individual endorsements.
Nausea: most-reported sensation, peaks weeks 4-8, manageable with low-fat meals 48 hr post-injection and morning dosing
Fatigue: more often reported in community than literature flags it - many users describe a "blah" first 2-3 weeks at each new dose step
"Reta burn" / sunburn-feeling skin: matches the dysesthesia signal, users describe it as a tingling/sunburn that comes and goes, more common at 8-12 mg
Loss of taste / food aversion: meaningful enough that some users describe it as "food doesn't appeal" rather than just "I'm not hungry" - milder on reta than tirz per anecdote
Sulfur burps: less common than on semaglutide, but reported
Heart rate awareness: users self-tracking with Apple Watch/Whoop commonly see +5-10 bpm resting HR; usually settles by week 12
Route: SubQ
Injection site: abdomen or outer thigh, rotate sites
Storage: refrigerated, ~28 days after reconstitution
Notes: Morning injection on a low-fat day reduces nausea per community reports. Keep unreconstituted vials refrigerated; allow to reach room temp before injecting once mixed. Use a fresh insulin syringe per draw, don't shake the vial (swirl gently to mix).