How do I cycle on and off peptides?
It depends on the peptide class. Growth hormone peptides (CJC-1295, ipamorelin, sermorelin): yes, cycle. Continuous use desensitizes the receptors in your pituitary, so the peptide stops working as well. Common protocol is 8 to 12 weeks on, 4 weeks off. Healing peptides (BPC-157, TB-500): used for a specific injury or healing protocol. Typical run is 4 to 8 weeks. No strict off cycle rule. GLP-1s (semaglutide, tirzepatide): NOT cycled. These treat a chronic condition. Stopping usually leads to weight regain.
- GH secretagogues (CJC-1295, ipamorelin, sermorelin): continuous use downregulates GHRH and GHS receptors in the pituitary
- Common GH peptide cycle: 8 to 12 weeks on, 4 weeks off
- Lee et al. 2018 (Yonsei Medical Journal): six weeks of continuous GHS administration abolished the GH stimulatory effect in rats
- Healing peptides: typical clinical duration 4 to 8 weeks per protocol; no established receptor downregulation comparable to GH secretagogues
- GLP-1s: weight regain is expected after stopping (about 65 to 70% within a year)
- Seeds Peptide Protocols Vol. 1 (ISBN 9780578624358) is the primary clinical reference for cycling protocols
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