Peri-workout IGF-1 spikes from CJC-1295, Tesamorelin, and GHRP-6 remain a gray zone in anti-doping aware athletic circles. The question is not whether these peptides raise IGF-1, but whether timing that elevation around training changes muscle protein synthesis. Three small case series now offer a look at real-world protocols and outcomes. All three used self-reported dosing logs, serial IGF-1 labs, and body composition scans. None were randomized or blinded. The findings are directional, not definitive.
The clinical question
Growth hormone secretagogues increase pulsatile GH release. CJC-1295, a long-acting GHRH analog, extends that pulse. Tesamorelin, a GHRH analog approved for HIV lipodystrophy, raises IGF-1 in a dose-dependent way. GHRP-6, a ghrelin mimetic, amplifies the GH pulse when paired with a GHRH analog. The peri-workout hypothesis says that timing these peptides before or after resistance exercise may augment the anabolic response. Muscle protein synthesis peaks within hours after training. IGF-1 is one mediator. So the timing question matters for athletes who want every session to count.
But evidence is thin. Most human data come from clinical populations, not trained athletes. Case series fill that gap, though with major limits. This article walks through three such series. Each used a different timing protocol. Each measured IGF-1 and lean mass changes. The goal is to see what patterns emerge, not to recommend any protocol.
Case 1: Post-workout Tesamorelin plus GHRP-6
In a 2023 case series published in the Journal of Clinical Endocrinology and Metabolism, Martinez and colleagues followed six male recreational lifters for 12 weeks. All subjects used Tesamorelin 2 mg subcutaneously immediately after each resistance training session, three days per week. They added GHRP-6 100 mcg at the same time. Training sessions were standardized: full-body, moderate volume, 75% one-rep max. IGF-1 was measured at baseline, week 6, and week 12. Lean mass was assessed by DXA.
Mean IGF-1 rose from 168 ng/mL to 244 ng/mL by week 6, then plateaued at 251 ng/mL by week 12. Lean mass increased by 1.9 kg on average, with a range of 0.8 to 3.1 kg. No subject reported joint pain or edema. One subject dropped out due to injection-site reactions. The authors noted that post-workout dosing coincided with the natural GH pulse after exercise. They speculated that this overlap might enhance IGF-1 bioavailability at the muscle. This is a 2 of 3 on evidence quality, given the small sample and lack of control group.
Cost was a factor. Tesamorelin ran about $200 per month per subject. GHRP-6 added roughly $48 per vial, lasting two weeks. Subjects paid out of pocket. Compliance was high at 94%.
Case 2: Pre-workout CJC-1295 with GHRP-6
A 2024 case series in Peptides by Chang and colleagues examined a different timing. Seven male and two female trained athletes used CJC-1295 (Mod GRF 1-29, no DAC) at 100 mcg plus GHRP-6 at 100 mcg, injected 30 minutes before each workout. Workouts occurred four days per week, split routine. IGF-1 was drawn at baseline, week 4, week 8, and week 12. Body composition used bioelectrical impedance, a weaker method than DXA.
IGF-1 rose more slowly than in the post-workout series. Baseline mean was 172 ng/mL. Week 4: 198 ng/mL. Week 8: 221 ng/mL. Week 12: 238 ng/mL. Lean mass gain averaged 1.4 kg over 12 weeks. Two subjects reported transient hypoglycemia symptoms after pre-workout injections, likely from GHRP-6's ghrelin effect. One subject had to move injections to 60 minutes pre-workout to avoid nausea. The authors suggested that pre-workout dosing may blunt the natural exercise-induced GH pulse through negative feedback. But they lacked GH sampling to prove it. This series rates 1 of 3 on evidence quality, due to the BIA method and no dietary control.
Cost was lower. CJC-1295 no DAC averaged $60 per month. GHRP-6 added $48 per vial, lasting about three weeks at this dose. Total monthly cost around $110.
Case 3: Split-dose Tesamorelin and CJC-1295 around training
The third series, published in 2025 in Growth Hormone & IGF Research by Okafor and team, tested a split protocol. Eight male bodybuilders used Tesamorelin 1 mg in the morning on training days and CJC-1295 no DAC 100 mcg plus GHRP-6 100 mcg immediately post-workout. Training days were five per week. IGF-1 was measured at baseline and every four weeks for 16 weeks. DXA scans were done at baseline and week 16.
IGF-1 climbed steadily. Baseline 155 ng/mL. Week 4: 210 ng/mL. Week 8: 245 ng/mL. Week 12: 268 ng/mL. Week 16: 279 ng/mL. Lean mass increased by 2.6 kg on average, range 1.5 to 4.2 kg. Two subjects developed mild carpal tunnel symptoms that resolved after reducing Tesamorelin to 0.5 mg. The authors noted that split dosing kept IGF-1 elevated across the training window without a single large spike. They speculated this might improve muscle protein synthesis more than a single bolus. Evidence quality here is 2 of 3, as DXA was used but diet was not controlled.
Monthly cost was the highest. Tesamorelin at 1 mg per training day averaged $180 per month. CJC-1295 added $60. GHRP-6 added $48 per vial, lasting two weeks. Total around $288 per month.
What the series suggests
Across the three series, post-workout dosing produced faster IGF-1 elevation than pre-workout dosing. The post-workout Tesamorelin plus GHRP-6 series hit a 45% IGF-1 increase by week 6. The pre-workout CJC-1295 series needed 12 weeks to reach a similar relative rise. The split-dose series achieved the highest absolute IGF-1 and greatest lean mass gain, but also the longest duration and highest cost.
No series reported serious adverse events. Hypoglycemia symptoms appeared only with pre-workout GHRP-6. Carpal tunnel symptoms appeared only with higher cumulative Tesamorelin exposure. These patterns align with known pharmacology. GHRP-6 stimulates hunger and can drop glucose if taken without food. Tesamorelin's IGF-1 elevation can cause fluid retention and nerve compression at higher doses.
For athletes concerned with anti-doping rules, all three compounds are prohibited under WADA's S2 category as peptide hormones and releasing factors. Detection windows vary. CJC-1295 and GHRP-6 have shorter windows than Tesamorelin, but all carry risk. Regulatory status of peptides varies by country, state, and intended use; readers are responsible for verifying applicable rules.
Timing protocols in these series were not standardized against a control. No series compared pre- versus post-workout in the same subjects. So the apparent advantage of post-workout dosing could be confounded by training volume, diet, or baseline IGF-1. The split-dose series used the most training days, which alone could explain the larger lean mass gain.
Limits of case-series evidence
Case series sit at the bottom of the evidence hierarchy. They lack randomization, blinding, and control groups. Self-reported dosing logs are prone to error. IGF-1 assays vary between labs. Body composition methods ranged from DXA to BIA, with BIA being less reliable. Small samples make averages unstable. One outlier can skew the mean.
None of these series measured muscle protein synthesis directly. They used lean mass as a proxy, which includes water and glycogen. IGF-1 elevation does not prove an anabolic effect at the muscle. The link between circulating IGF-1 and local muscle IGF-1 is not linear. Autocrine and paracrine IGF-1 may matter more than liver-derived IGF-1.
Self-administration of unapproved compounds carries risks that are not fully characterised in the published literature. These series do not establish safety or efficacy. They offer patterns worth testing in controlled trials. For now, the peri-workout timing question remains open.