Understand the source comparison
Peptides and CrossFit Synergy Timing Protocol: Comparison of Administration Windows
BPC-157, TB-500 20–30 min pre-workout Exercise-induced tissue perfusion and mechanical stress localise peptide to injury sites via enhanced capillary recruitment Post-workout or at rest Without active blood flow and tissue loading, peptides distribute systemic
No winner is assigned.
This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- BPC-157, TB-500
- 20–30 min pre-workout
- Exercise-induced tissue perfusion and mechanical stress localise peptide to injury sites via enhanced capillary recruitment
- Post-workout or at rest
- Without active blood flow and tissue loading, peptides distribute systemically rather than concentrating in target tissues. Efficacy drops by 60–70%
- CJC-1295/Ipamorelin, GHRP-2
- 45–75 min post-workout, fasted state
- Timing to refractory period after endogenous GH pulse maximises pituitary response; fasting avoids leucine-mTOR suppression of GH
- Immediately post-workout or with protein intake
- Leucine from post-workout protein suppresses GH secretion by 50–60%; dosing during natural GH peak causes receptor saturation
- MK-677 (Ibutamoren)
- 30–60 min before sleep
- Amplifies nocturnal GH pulse during slow-wave sleep when protein synthesis rates are highest
- Morning or pre-workout
- MK-677 has a 24-hour half-life. Morning dosing causes daytime lethargy and disrupts natural GH circadian rhythm
- Thymalin
- Post-workout or before bed
- Thymic peptide supporting immune recovery; timing to align with cortisol clearance post-training
- During workout (no exercise-specific benefit)
- Thymalin works through immune modulation, not exercise windows. Post-training allows it to counteract exercise-induced immunosuppression
- Bottom Line / Professional Assessment
- Pre-workout for injury peptides, post-workout (fasted) for GH secretagogues, pre-sleep for MK-677
- Each class targets different physiological windows. Stacking everything at one time negates the timing-dependent mechanisms
- Arbitrary 'morning injection' dosing for all peptides
- Timing peptides to metabolic windows increases efficacy by 2.5–3× compared to convenience-based dosing; the cost is the same but the outcome is not