Most retatrutide dosage pages print one ladder and pretend it is the ladder. Lilly has used two. Forums built a third. Pens, clicks, and “how many units is 2mg” sit in a fourth pile of search results that never mention how much water went in the vial.
Retatrutide is Lilly’s once-weekly triple agonist: GIP, GLP-1, glucagon. Tirzepatide already hits the first two. Glucagon is the extra lever — more energy out, not just less food in. Phase 2 ran in NEJM. Five Phase 3 studies have read out. July 23, 2026 Lilly said it will file a BLA in Q1 2027. Still unapproved. A compounding pharmacy cannot hand you a bag of it. Research catalogs often hide it under a house name.
On Everest that name is GLP-3 RT. Same peptide. Freedom Diagnostics HPLC, COA on the listing, 10mg / 20mg / 30mg, sale from $52.49. Code BRAINFLOW is 10% off.
The BrainFlow Take
Phase 3 is the schedule Lilly is taking to the FDA: 2mg first, step every four weeks, 6mg and 9mg exist so nobody has to jump 4→8→12. The 1→2→4→8→12 chart is what Discord runs because a 10mg vial portions that way and a 2mg first pin is a lot of peptide on a cold gut. r/Retatrutide 2026 beginner threads start even lower — 0.5–1mg — then crawl. Split pins (MWF) show up when a single weekly hit is brutal. Faster climbs are how people quit in the trial data.
Four weeks, then step. Hold if GI is still ugly.
Every trial. Not a “more is better” button.
80 weeks, no diabetes. ~71 lb in that arm’s pound chart.
Usual landing zone. First-timers start lower, 0.5–1mg.
BLA planned Q1 2027. No pharmacy compounding exception.
Same day. Half-life ~6 days. Do not double a missed pin.
Phase 2 vs Phase 3 vs the Chart Everyone Screenshots
Phase 2 obesity, Jastreboff, NEJM 2023, 338 adults. Flat 1mg arm, plus arms that climbed toward 4, 8, or 12mg, starting at 2mg or 4mg depending on the group. That is the chart most Google results still reprint.
Phase 3 TRIUMPH / TRANSCEND starts everyone at 2mg. Steps every four weeks. 4mg is one step. 9mg is 2 → 4 → 6 → 9. 12mg is 2 → 4 → 6 → 9 → 12. Lilly put 6 and 9 in because jumping 4 → 8 → 12 was chewing people up on nausea. If you follow one official schedule, follow this one. It is the program they are filing on.
| Weeks | Phase 2 (older) | Phase 3 (current) |
|---|---|---|
| 1–4 | 1mg or 2mg | 2mg |
| 5–8 | 4mg | 4mg |
| 9–12 | 8mg | 6mg |
| 13–16 | 12mg | 9mg |
| 17+ | Hold | 12mg or hold at 9 |
Coming off tirzepatide or semaglutide, people rarely drop to 0.5mg. They usually land in the 2–4mg neighborhood and watch the gut for two weeks before moving. First-timers with no GLP-1 history are the ones who belong on 0.5–1mg, not because the trial said so — the trial started at 2mg — but because the trial also had nurses and a dropout column.
Screenshot chart
Weeks 1–4: 1mg. Then 2, 4, 8, 12. One pin a week. Sit an extra month on a rung if food is still a problem.
Filing schedule if you want it instead: 2mg → 4 → 6 → 9 → 12, four weeks each. Same weekly cadence.
Listed as GLP-3 RT · not the generic name
Everest GLP-3 RT — 10mg, 20mg, 30mg
Freedom Diagnostics HPLC, COA on the page, 99%+ claim. Sale from $52.49. That is the cheap vial with a ticket attached. Search the catalog for GLP-3 RT. Code BRAINFLOW is 10% off any size.
Research use only. Sale prices move.
What People Lost in the Trials
Phase 2, 48 weeks: 8.7% at 1mg, 17.1% at 4mg, 22.8% at 8mg, 24.2% at 12mg, 2.1% placebo. At 12mg every subject lost at least 5%. 93% lost 10%+. 83% lost 15%+. The curve was still falling when the trial ended.
TRIUMPH-1, 80 weeks, no diabetes: 19.0% at 4mg, 25.9% at 9mg, 28.3% at 12mg. Just over 45% on 12mg lost 30% of starting weight. Extension in BMI ≥35: 30.3% at 12mg by week 104. TRIUMPH-4 (knee OA): 28.7% at 12mg. TRIUMPH-2 (type 2 diabetes + obesity): 20.8% at 12mg — diabetes usually blunts this class.
| Trial | Time | 12mg result |
|---|---|---|
| Phase 2 NEJM | 48 weeks | 24.2% |
| TRIUMPH-1 | 80 weeks | 28.3% |
| TRIUMPH-1 extension | 104 weeks | 30.3% |
| TRIUMPH-4 | 68 weeks | 28.7% |
| TRIUMPH-2 (T2D) | 80 weeks | 20.8% |
| TRIUMPH-1, 80 weeks | Average pounds |
|---|---|
| 4mg | 47.2 lb |
| 9mg | ~64 lb class |
| 12mg | ~71 lb class |
Cross-trial vs semaglutide and tirzepatide makes retatrutide look ahead. TRIUMPH-5 is the actual head-to-head with tirzepatide. It has not reported. Do not treat separate studies as a cage match.
How to Mix a 10mg, 20mg, or 30mg Vial
Lyophilized cake, bacteriostatic water down the glass wall, roll until it disappears, cap labeled with mg/mL, U-100, fat of the abdomen or thigh. These come in a 3mL vial — 2.0 mL into a 10mg is the clean chart, 3.0 mL into a 30mg is the maintenance chart. Injecting the whole 10mg because “it says 10 on the bottle” is the mistake that writes itself.
| 10mg + 2.0 mL | 30mg + 3.0 mL | |
|---|---|---|
| Concentration | 5 mg/mL | 10 mg/mL |
| 1mg | 20 units | 10 units |
| 2mg | 40 units | 20 units |
| 4mg | 80 units | 40 units |
| 8mg | 160 units (1.6 mL) | 80 units |
| 12mg | 240 units — split draws | 120 units |
Same day each week. Time of day does not show up as a trial variable. A lot of people pin at night and sleep through the first wave of nausea. Missed dose: if several days remain, take it. If the next pin is close, skip. Never stack two weeks into one syringe. That is borrowed from semaglutide / tirzepatide labels, not a retatrutide package insert, because there is not one.
What Hits You
Nausea, diarrhea, vomiting, the usual GLP-1 gut file, worse as the milligrams climb, worst in the first days after a step. Phase 2 serious adverse events sat near placebo. Resting heart rate drifted up, peaked around week 24, then eased. Glucagon activity is the extra reason to watch rate and glucose, which dual agonists do not add in the same way.
Class cautions that follow this family: personal or family MTC or MEN2, prior serious reaction to a GLP-1, pregnancy. Flag pancreatitis history, bad gastroparesis, active gallbladder disease, rough kidneys or liver with a clinician. Small meals, bland for a day after a step-up, skip the grease and the whiskey that week.
Where This Stands in September 2026
Not FDA-approved. No brand name. Lilly said July 23, 2026 it will file a BLA in Q1 2027. That is a filing plan. No PDUFA date. TRIUMPH-4, TRANSCEND-T2D-1, TRIUMPH-1, TRIUMPH-2, TRIUMPH-3 have all read out positive. Outcomes trial runs into 2028–29. Head-to-head with tirzepatide still running.
You cannot walk into a compounding pharmacy and get a retatrutide prescription the way people did with semaglutide and tirzepatide during shortage. Those two were approved drugs on the shortage list. Retatrutide has never been approved and has never been on that list. September 2025 FDA warning letters went after sellers making treatment claims. Research-use labeling with no disease claims is the lane this market sits in. That is not a pharmacy bag.
Where to Buy — Search GLP-3 RT
A triple agonist is a large peptide. No COA, no buy. Everest does not title the page “Retatrutide.” It is GLP-3 RT at /product/glp-1r/. Freedom Diagnostics HPLC, 99%+, certificate on the listing, 10mg / 20mg / 30mg in a 3mL vial. Sale from $52.49. That undercuts a lot of shops still asking $80–150 for a 10.
Code BRAINFLOW takes another 10% off the sale.
10mg vial
From $52.49
Low-rung months. Fine first vial.
Then step to 20 or 30
30mg vial
Top sale tier
Maintenance. Best cost per milligram on the page.
Same COA standard
Cheap for a tested triple
Everest GLP-3 RT
10 / 20 / 30mg. Freedom Diagnostics. Search GLP-3 RT so you land on the right SKU. Code BRAINFLOW is 10% off.
Get GLP-3 RT →FAQ
What dose do people start at?
Phase 3 starts at 2mg. Forums often start at 1mg. Top studied dose is 12mg weekly.
Why do shops list it as GLP-3 RT?
Catalog name for research-grade retatrutide. Look for 10, 20, and 30mg on the same page.
Is it stronger than tirzepatide?
Separate trials look that way. TRIUMPH-5 is the head-to-head. Not out.
Can a pharmacy compound it?
No. Never approved, never on the shortage list. Research suppliers only.
Is it FDA-approved?
No. Lilly plans to file Q1 2027.
Bottom Line
Two Lilly schedules. One screenshot schedule. Start lower than Phase 3 if you have never touched a GLP-1. Start closer to 2–4mg if you are rolling off Mounjaro. Mix the vial so 1mg is a number on the barrel you can see. Five positive Phase 3s, still unapproved, and the research SKU is cheaper than most shops want to admit if you search the catalog name.
Everest GLP-3 RT — 10mg / 20mg / 30mg — code BRAINFLOW saves 10%
Retatrutide / GLP-3 RT is investigational and not FDA-approved. Sold as a research compound for laboratory use only. Not pharmacy-compoundable. Educational, not medical advice.
Affiliate links to Everest Peptides. BrainFlow may earn a commission at no extra cost to you.
Last updated: September 2026
