Peptide cycling: how long to run a peptide and when to take a break

The first reason is receptor desensitization. Some receptors downregulate under constant stimulation, so the same dose does less over time. Kisspeptin-10 is the clearest case: continuous exposure desensitizes its receptor, which is why the compound page describes every-other-day dosing or regular breaks. IGF-1 LR3 protocols run 4 to 6 weeks on and 4 off on the theory that IGF-1 receptors downregulate. Semax users report some tolerance to the alerting effect with continuous daily use, which is one reason for its 10 to 20 day courses.

The second reason is that the goal has an end point. BPC-157 and TB-500 are used to heal injuries, and when the injury has healed there is nothing left to treat. The compound pages describe people running them until recovery and restarting only if needed. Melanotan-1 and -2 have a loading phase that ends when the desired shade is reached, after which maintenance is once or twice weekly or nothing at all over winter.

The third reason, and the most common, is caution. Most peptides on this site have no long-term human safety data, and a 4 to 8 week run followed by a break is the convention people adopt when nobody knows what a year of continuous use does. GHK-Cu injectable, MOTS-c, SS-31, KPV, 5-Amino-1MQ and SLU-PP-332 all carry that pattern on their compound pages, and in each case the page says the break is a convention rather than a finding.

The GHRP and GHRH analogs have the most consistent cycling convention. Ipamorelin runs 8 to 16 weeks with a few weeks off and an IGF-1 check before the next run. CJC-1295 without DAC follows the same 8 to 16 weeks, and the compound page notes there is no strong evidence the GHRH receptor desensitizes, so the break is a convention. CJC-1295 with DAC runs 8 to 12 weeks, sometimes tapering to a single 500 mcg dose in the last week, then about 4 weeks off until IGF-1 returns to baseline.

The two clinic-prescribed GHRH analogs run longer. Sermorelin is typically prescribed continuously for 3 to 6 months before an IGF-1 recheck, and many patients stay on it long term with occasional breaks; some protocols use 5 nights on and 2 off. Tesamorelin is not cycled at all: the approved regimen is continuous daily use, visceral fat returns within months of stopping, and there is no trial data on intermittent use. HGH itself runs 3 to 6 months minimum for body composition, with 4 to 8 weeks off if IGF-1 or glucose drift up.

The practical check for this whole class is bloodwork. IGF-1 rises within a couple of weeks of starting and tells you the protocol is doing something; fasting glucose and HbA1c tell you whether it is doing too much. A cycle that ends when IGF-1 is checked and found reasonable is better grounded than one that ends on week 12 because a forum said so. The CJC-1295 and ipamorelin stack page covers the combined cycle, and ipamorelin vs sermorelin covers why the two cycle differently.

BPC-157 runs 4 to 8 weeks and then a reassessment, with a 2 to 4 week break, or simply stops once the injury has healed. The compound page is clear that there is no loading, no taper and no human data on whether continuous use is better or worse than cycling. The reported range is 250 to 500 mcg once or twice daily throughout.

TB-500 is the one healing peptide with a shaped cycle: a 4 to 6 week loading phase at 2 to 2.5 mg twice weekly, then either a drop to 2 mg every one to two weeks for maintenance or a full stop, with a 4 to 8 week break before any repeat. The compound page notes that loading is a community convention rather than something from a human trial, and that many people just dose twice weekly for the whole cycle. The Wolverine stack of BPC-157 and TB-500 usually follows the TB-500 shape.

The deciding variable for this class is the injury. A tendon that has stopped hurting and regained range of motion is the stop signal, and the compound pages for both frame restarting as something done only if needed. People running healing peptides continuously as prevention are outside anything the data describe. The healing guide covers the compounds, and BPC-157's 2026 regulatory status covers why the supply side is in flux.

The melanocortins cycle around an outcome. Melanotan-1 uses a 2 to 4 week loading phase of daily injections until the desired shade, then once or twice weekly maintenance, and many people stop for winter and reload in spring. Melanotan-2 is the same shape with a 2 to 3 week load, often starting at 0.25 mg to test nausea, and many switch to melanotan-1 for maintenance. PT-141 is not cycled; it is used per occasion with a label cap of one dose per 24 hours and eight per month.

The nootropic peptides use short courses. Semax runs 10 to 20 days then a break of similar length, partly because of reported tolerance to the alerting effect. Selank runs 2 to 3 weeks then 1 to 3 weeks off, and many users skip cycling and use it only on specific stressful days. DSIP runs 1 to 3 weeks then a break, or intermittently, because nightly long-term use produces fading or unpredictable responses for some people.

The Russian bioregulators are the shortest and least frequent. Epithalon and Pinealon both run 10 to 20 day courses repeated once or twice a year, which mirrors the elderly studies they come from. There is no loading, no taper, and several months between courses. Running them longer at lower doses has no data behind it, as the compound pages say.

GLP-1 drugs are the big one. Semaglutide, tirzepatide, retatrutide and cagrilintide are not cycled. The dosage is a titration ladder held at a maintenance step indefinitely, and the withdrawal studies show most of the lost weight returning within a year of stopping. Stopping is done as a taper, not a break, and a planned off-cycle makes no sense for a drug whose entire effect depends on being present. The microdosing article covers the reduced-dose maintenance idea, which is also untested.

Topical peptides are continuous. GHK-Cu cream, SNAP-8 and AHK-Cu on the scalp work only while in use, and the compound pages describe judging results at 2 to 6 months rather than cycling. Only GHK-Cu's injectable form carries a 4 to 8 week convention, mainly because of theoretical copper load. GHK-Cu for hair covers the topical side.

Tesamorelin, as above, is continuous by label. Glutathione and NAD+ are run either ongoing or in loose blocks with no established break, and their compound pages say there is no evidence cycling matters. VIP in the CIRS protocol is held 1 to 3 months at full dose then tapered over 2 to 4 weeks rather than stopped, with some people staying on a low maintenance dose.

Start from the goal. If the goal is an injury, the cycle ends when the injury does. If the goal is a tan, it ends at the shade. If the goal is a blood marker, IGF-1 for the growth hormone class, LH and testosterone for kisspeptin, glucose and HbA1c for anything that might push them, the cycle ends when the marker is checked and the result is reasonable. A cycle defined by an outcome is easier to judge than one defined by a week count.

Then check what the compound page says about the receptor. Where desensitization is documented, as with kisspeptin, or theorized, as with IGF-1 LR3, the break has a mechanism behind it. Where the page says the break is a convention, as with ipamorelin and CJC-1295 without DAC, the break is still reasonable but the calendar is negotiable and bloodwork is the better guide.

Finally, treat the absence of long-term data as the default reason to stop. Most compounds on this site have never been studied for a year of continuous use in a person, and a planned break is the only tool available for noticing a problem that short studies would miss. The peptide dosage chart lists the research level for every compound, and how long peptides last covers the half-life side of the same question.