Guides, tools & half-life data
Every number on these pages comes from an FDA label or a published human pharmacokinetic study, and every page links its sources. Where the evidence is thin, the page says so instead of guessing.
Free tools
Peptide dose calculator
Vial strength, bacteriostatic water and your dose in; exact units out. Supports U-100 in all three barrel sizes, U-40 and tuberculin syringes. Runs in your browser, no signup.
Half-life chart
All 38 compounds in one sourced table: half-life, time to peak, dosing cadence and how long a dose takes to clear.
Choosing an app
Best GLP-1 & peptide tracker apps
Twelve apps compared on what each one actually advertises, with App Store ratings and an honest account of where Bo falls short.
Shotsy alternatives
When to stay with Shotsy, and when another app genuinely fits better.
MeAgain alternatives
When to stay with MeAgain, and when another app genuinely fits better.
Pep AI alternatives
When to stay with Pep AI, and when another app genuinely fits better.
By medication
What a tracker needs to get right for each medication, and how its half-life shapes the schedule.
- Ozempic tracker app semaglutide, once weekly
- Wegovy tracker app semaglutide, once weekly
- Mounjaro tracker app tirzepatide, once weekly
- Zepbound tracker app tirzepatide, once weekly
- Retatrutide tracker app retatrutide, once weekly in trial protocols
Practical guides
- How to reconstitute a peptide the step sequence, and what ruins a vial
- Bacteriostatic water what the preservative does, and the 28-day convention
- GLP-1 injection sites and rotation what the FDA labels specify
- Missed a GLP-1 dose the 48-hour rule and why it exists
- How long does it stay in your system the five half-life rule
Half-life by compound
Compounds marked "limited data" have no FDA label or full human pharmacokinetic study behind them. Those figures are the best published estimate and should be read as directional.
GLP-1 & metabolic
- Tirzepatide 5 days (120 hours)
- Semaglutide (injectable) 7 days (168 hours)
- Semaglutide (oral) 7 days (168 hours)
- Liraglutide 13 hours
- Dulaglutide 5 days (120 hours)
- Exenatide (immediate release) 2.4 hours
- Retatrutide 6 days (144 hours)
- Survodutide 6 days (144 hours)
- Cagrilintide 7.5 days (180 hours)
- Orforglipron 40 hours
- Tesofensine 9.2 days (220 hours) · limited data
- 5-Amino-1MQ 4 hours · limited data
Growth hormone secretagogues
- Tesamorelin 30 minutes
- MK-677 (Ibutamoren) 24 hours
- CJC-1295 (with DAC) 7 days (168 hours) · limited data
- Ipamorelin 2 hours · limited data
- Sermorelin 12 minutes
- GHRP-2 30 minutes · limited data
- GHRP-6 18 minutes · limited data
- Hexarelin 54 minutes · limited data
- HGH Fragment 176-191 30 minutes · limited data
- AOD-9604 30 minutes · limited data
Other research peptides
- PT-141 (Bremelanotide) 2.7 hours
- BPC-157 4 hours · limited data
- TB-500 (Thymosin β4) 6 hours · limited data
- GHK-Cu 1 hours · limited data
- MOTS-c 3 hours · limited data
- NAD+ 2 hours · limited data
- Epitalon 1 hours · limited data
- Thymosin Alpha-1 2 hours · limited data
- KPV 1 hours · limited data
- SS-31 (Elamipretide) 3 hours · limited data
- Semax 30 minutes · limited data
- Selank 30 minutes · limited data
- DSIP 15 minutes · limited data
- Kisspeptin 30 minutes · limited data
- Oxytocin 9 minutes · limited data
- Melanotan II 1 hours · limited data
Where this data comes from
These are the same constants Bo's estimated-levels feature uses to draw your personal curve. The app takes your actual logged doses and models what is still in your system between shots. Who writes these guides and the rules they follow →
Educational information only. Bo is a tracking app, not a medical device, and nothing here is medical advice, a dosing recommendation, or a substitute for your prescriber. Half-lives are population averages from the sources cited on each row; individual clearance varies with body weight, kidney and liver function, and other medication.