Tirzepatide dosing protocol
Start tirzepatide at 2.5 mg once a week. Inject subQ in your abdomen, thigh, or upper arm. Stick to that for 4 weeks. Then bump to 5 mg at week 5. If it sits well, hit 7.5 mg at week 9 and 10 mg by week 13. From week 17, you can push to 12.5 mg or even 15 mg (Mounjaro (tirzepatide) FDA Prescribing Information §2.1; max 15 mg weekly, escalated in 2.5 mg increments after at least 4 weeks).
Take a 10 mg vial and add 2 ml bacteriostatic water. You get 5 mg/ml. First dose of 2.5 mg means drawing 0.5 ml, or 50 units on a 1 ml insulin syringe. That vial handles your first 4 weeks perfectly.
Here's the week-by-week:
- Weeks 1-4: 2.5 mg (0.5 ml)
- Weeks 5-8: 5 mg (1 ml)
- Weeks 9-12: 7.5 mg (1.5 ml)
- Weeks 13+: 10 mg (2 ml), then higher if pushing to 15 mg
Pick any day of the week and stick to it. You only dose once a week because tirzepatide has a roughly 5-day elimination half-life (Mounjaro FDA PI §12.3). Miss one? The Mounjaro label says administer the missed dose within 4 days (96 hours); if more than 4 days have passed, skip it and resume on your regular day (Mounjaro FDA PI §2.4). Use our Tirzepatide calculator to nail your syringe marks.
Semaglutide dosing protocol
Semaglutide ramps up slow, which I like if you're easing in. Begin with 0.25 mg weekly subQ for 4 weeks. Then 0.5 mg weeks 5-8. Up to 1 mg weeks 9-12. Then 1.7 mg weeks 13-16, and the standard maintenance dose of 2.4 mg from week 17 (Wegovy (semaglutide) FDA PI §2.2; 0.25/0.5/1/1.7/2.4 mg titrated every 4 weeks). Note 2.4 mg is the standard maintenance and maximum dose for most people; the 2025 Wegovy label also includes an additional 7.2 mg higher-dose (HD) maintenance option that is FDA-approved when further weight reduction is clinically indicated (Wegovy FDA PI).
For a 10 mg vial, add 2.5 ml bacteriostatic water. That's 4 mg/ml. Your first 0.25 mg dose is 0.06 ml, about 6 units. Tricky to measure, so hit the Semaglutide calculator.
Full rundown:
- Weeks 1-4: 0.25 mg (0.06 ml)
- Weeks 5-8: 0.5 mg (0.13 ml)
- Weeks 9-12: 1 mg (0.25 ml)
- Weeks 13-16: 1.7 mg (0.43 ml)
- Week 17+: 2.4 mg (0.6 ml)
One 10 mg vial lasts 40 weeks on starters or just 4 weeks at max dose. Inject weekly on the same day. Semaglutide has a roughly 1-week (~165 h) elimination half-life (Wegovy FDA PI §12.3), so the timing is forgiving. If you're under 5 days late, just do it; if more than 5 days have passed, skip the missed dose and resume on schedule (Wegovy FDA PI §2.4).
Retatrutide dosing protocol
Retatrutide is a triple agonist that hits GLP-1, GIP, and glucagon receptors (Jastreboff AM et al., Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial, NEJM 2023, PMID 37366315). The phase 2 trial did not use a uniform 1-mg start: it tested target doses of 1, 4, 8, and 12 mg weekly, with initial doses of 2 mg or 4 mg and group-specific escalation (Jastreboff 2023, NEJM, PMID 37366315). The schedule below is a community-reported titration ladder, not the trial protocol: start at 1 mg weekly subQ and add 1 mg every 4 weeks (2 mg weeks 5-8, 4 mg weeks 9-12, 8 mg weeks 13-16, up to 12 mg).
Add 2 ml bacteriostatic water to your 10 mg vial for 5 mg/ml. 1 mg is 0.2 ml, or 20 units. Everything scales from there.
What most people run:
- Weeks 1-4: 1 mg (0.2 ml)
- Weeks 5-8: 2 mg (0.4 ml)
- Weeks 9-12: 4 mg (0.8 ml)
- Weeks 13+: 6 mg (1.2 ml) or 8 mg (1.6 ml)
A 10 mg vial gives 10 shots at 1 mg or about 1.25 at 8 mg. The highest dose studied in the phase 2 trial was 12 mg weekly (Jastreboff 2023, NEJM, PMID 37366315); the idea that most users settle at 4 to 8 mg is community-reported, not from the trial. Check the Retatrutide calculator for your needs. Weekly, same day.
Reconstitution guide for 10 mg vials
You get these in 10 mg lyophilized vials. Stick to bacteriostatic water. Sterile water alone won't cut it without the preservative.
Tirzepatide 10 mg vial:
Add 2 ml bac water down the side. Swirl gently. 10 mg / 2 ml = 5 mg/ml.
- 2.5 mg = 0.5 ml (50 units)
- 5 mg = 1 ml (100 units)
- 10 mg = 2 ml (200 units)
Semaglutide 10 mg vial:
2.5 ml bac water = 4 mg/ml.
- 0.25 mg = 0.06 ml (~6 units)
- 1 mg = 0.25 ml (25 units)
- 2.4 mg = 0.6 ml (60 units)
Retatrutide 10 mg vial:
2 ml bac water = 5 mg/ml.
- 1 mg = 0.2 ml (20 units)
- 4 mg = 0.8 ml (80 units)
- 8 mg = 1.6 ml (160 units)
Grab a 3 ml syringe for the water. Let it sit 5 minutes, then swirl. No shaking. Draw into U-100 insulin syringes. Store extras in pens if you can. Calculators above handle body-weight tweaks.
Weekly injection protocols compared
Once a week, subQ. Abdomen two inches from navel, thigh, or back of upper arm. Rotate spots. 29-31 gauge, half-inch needles.
Sunday mornings suit most. Phone alarm helps.
Tirzepatide kills hunger fast thanks to its dual action. Some users report more early nausea on the 2.5 mg start than on semaglutide's tiny 0.25 mg, but that is anecdotal. No published head-to-head trial compares week-one nausea at these specific starting doses.
Semaglutide titrates slowest, so fewer sides. Empty stomach if it bugs you.
Some users say retatrutide's glucagon activity keeps energy up with less of a slump, and that 1 mg can feel like 5 mg tirzepatide. Those are subjective reports. No pharmacology or trial backs a 1 mg retatrutide ≈ 5 mg tirzepatide potency equivalence, so start low.
Some community protocols stack 250 mcg AOD-9604 daily or 300 mcg Ipamorelin at night for extra fat burn, but that is anecdotal. AOD-9604 did not show clinical fat-loss efficacy in trials, and ipamorelin has no fat-loss trial data.
Missed? Under 3 days, inject now and resume. 3-5 days, skip to next. Over 5, drop back down.
Stability and storage differences
Fridge them at 2-8 C, away from the freezer door. They break down at different rates once mixed.
Tirzepatide: People commonly handle it as if it keeps for about 30 days in bac water in the fridge, but that is just a community estimate. No published beyond-use-date or stability study exists for compounded or research tirzepatide reconstituted from lyophilized vials. Aliquot after the first draw into syringes or pens. Each poke risks junk. The dry-vial figures (freezes ~2 years at -20 C, fridges ~6 months) are also community handling estimates, not a primary stability source.
Semaglutide: Users call it the toughest of the bunch, with some citing 60+ days fridged. No published data backs a 60-day reconstituted shelf life, so treat that as anecdotal. Freeze the powder and thaw once. Wrap in foil, it hates light.
Retatrutide: This one is the least studied. No stability study exists for reconstituted retatrutide, so treat 28 days max fridged as a community estimate that may be optimistic. Freeze 1 ml aliquots at -20 C. To be safe, avoid room temp over 24 hours.
General handling guidance (community/handling estimates rather than primary stability data; for compounded products, beyond-use dating should follow USP <797>):
- Room temp under 25 C: keep brief; 21 days is a community-reported ceiling, not a validated figure.
- Freeze dry vials flat.
- Toss if cloudy or off-color.
- Travel with an ice pack and use promptly (community estimate ~48 hours).
For gut woes, some community protocols use 500 mcg BPC-157 plus 2.5 mg TB-500 weekly. Reports that it eases nausea are anecdotal. No clinical study shows BPC-157 or TB-500 reduce GLP-1-associated nausea, and neither has human PK or efficacy trials.
Side-by-side dosing chart
| Week | Tirzepatide | Semaglutide | Retatrutide |
|---|---|---|---|
| 1-4 | 2.5 mg | 0.25 mg | 1 mg |
| 5-8 | 5 mg | 0.5 mg | 2 mg |
| 9-12 | 7.5 mg | 1 mg | 4 mg |
| 13-16 | 10 mg | 1.7 mg | 6-8 mg |
| 17+ | 12.5-15 mg | 2.4 mg | 8-12 mg |
Tirzepatide escalates in 2.5 mg increments after at least 4 weeks to a max of 15 mg weekly (Mounjaro FDA PI §2.1), and semaglutide titrates 0.25/0.5/1/1.7/2.4 mg every 4 weeks (Wegovy FDA PI §2.2). The retatrutide column reflects a community titration ladder, not the phase 2 trial protocol (Jastreboff 2023, NEJM, PMID 37366315).
Volumes from 10 mg vial (standard reconns above):
| Dose | Tirz (5 mg/ml) | Semag (4 mg/ml) | Retatr (5 mg/ml) |
|---|---|---|---|
| 0.25 mg | N/A | 0.06 ml | N/A |
| 1 mg | 0.2 ml | 0.25 ml | 0.2 ml |
| 2.5 mg | 0.5 ml | N/A | N/A |
| 5 mg | 1 ml | N/A | 1 ml |
| 10 mg | 2 ml | N/A | 2 ml |
Managing common sides and protocols
Nausea is the most common side effect, but the rates are drug-specific and reflect overall trial incidence, not just weeks 1-2: semaglutide 2.4 mg caused nausea in about 44% of patients in STEP 1 (Wilding JPH et al., NEJM 2021, PMID 33567185), while tirzepatide nausea runs up to roughly 33% (Mounjaro/Zepbound USPI §6.1). Small bland meals 30 minutes after help. Ginger tea is a reasonable home measure; some community protocols add DSIP at night, but there is no evidence supporting DSIP for nausea and typical community dosing is in the microgram range (the previously listed 10 mg figure appears erroneous), so treat this as unsupported.
Tirzepatide: It's a dual GIP/GLP-1 receptor agonist and its GI side effects (nausea, vomiting, diarrhea) are dose-related (Mounjaro/Zepbound USPI §12.1, §6.1; SURMOUNT-1, Jastreboff 2022, NEJM, PMID 35658024). Pinning GI effects specifically on the GIP component is an oversimplification. Vomiting? Hold at 2.5 mg.
Semaglutide: Heartburn at 1 mg and up. Antacids in between.
Retatrutide: Claims of less nausea, better muscle retention, and a liver-enzyme threshold at 12 mg are community talk, not evidence. In the phase 2 trial, GI events were the most common adverse events, and nothing published shows a lean-mass-sparing advantage or a 12 mg liver-enzyme cutoff (Jastreboff 2023, NEJM, PMID 37366315).
Drink 3-4 liters water daily. Some community protocols pair 5 g creatine with 10 mg MOTS-c weekly (MOTS-c is dosed in milligrams, not grams) to support muscle, but the muscle-sparing claim is preclinical and unproven in humans.
Energy low? Some community protocols use 100 mcg Semax nasal in the mornings or 300 mcg Sermorelin nightly. Both are community doses, and neither has evidence as an energy or fatigue fix.
Cost and vial math for 3 months
12 weeks at maintenance:
- Tirzepatide: Weeks 1-4: 1x10 mg vial. Weeks 5-12: ~45 mg = 5x10 mg vials. Total 6.
- Semaglutide: Weeks 1-12: ~8.75 mg = 1x10 mg vial.
- Retatrutide: Weeks 1-12: ~30 mg = 3x10 mg vials.
Bulk 10 mg vials. Semaglutide wins cheap long-term.
Which one for you?
New to these? Semaglutide at 0.25 mg.
Aggressive cut? Tirzepatide to 15 mg.
Keep muscle on recomp? Retatrutide at 8 mg.
Weigh weekly. Up every 4 weeks if stuck. As a community protocol (not clinically validated), some add a 1 mg CJC-1295 / Ipamorelin blend 5 nights a week for a GH pulse.
This info is for educational purposes only. Consult a healthcare professional before using any peptides, as they can have significant effects and interactions. Individual results vary. To be precise: semaglutide (Wegovy) and tirzepatide (Zepbound) are FDA-approved for chronic weight management, while retatrutide is still investigational, with its phase 3 program ongoing and no FDA approval as of 2026 (Wegovy FDA PI; Jastreboff 2023, NEJM, PMID 37366315).
References
- Jastreboff AM, Kaplan LM, Frías JP, et al. "Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial." N Engl J Med, 2023. PubMed
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. "Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1)." N Engl J Med, 2022. PubMed
- Wilding JPH, Batterham RL, Calanna S, et al. "Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1)." N Engl J Med, 2021. PubMed
- Mounjaro (tirzepatide) Prescribing Information. U.S. Food and Drug Administration, 2025. FDA Label
- Wegovy (semaglutide) Prescribing Information. U.S. Food and Drug Administration, 2025. FDA Label