CommunityConditions & Comorbidities

Unexpected IGF-1 Tesamorelin Lab

4 replies3 peopleJan 21, 2026☆ Follow
Summary

Why would IGF-1 rise after stopping tesamorelin, especially with major weight loss and no other peptides?

The original poster saw IGF-1 climb from 108 to 188 on tesamorelin, then reach 202 a month after stopping it entirely while losing 38 lb on tirzepatide and another GLP-1. One reply suggested the level may have peaked later and not yet declined. Another detailed how weight loss can reduce GH resistance, improve hepatic sensitivity, and allow IGF-1 to rebound even without the peptide, plus possible effects from stress, inflammation, or assay variation.

What this discussion establishesStill open

Whether the January 2026 value will stay elevated or drop on a March retest.

Nothing here is advice.

4 replies · 3 people
IronThistle42archiveopening postJan 21

Quick summary, after I quit tesamorelin my IGF-1 went up instead of down. July 16 2025 it was 108. Started tesa at 2 mg a day on August 6. August 26 it was 188 while still taking it daily. Quit completely on December 8 ahead of heart surgery and never restarted. January 16 2026 it was 202, with only tirz and survo stacked the whole period. All tests through Labcorp. Dropped 38 lb from August to December. That result on January 16 was not what I expected. Any thoughts?

PlainCompass54archiveJan 21

My guess is your IGF-1 kept climbing between August and December and simply has not dropped back down yet.

IronThistle42archiveJan 21
↳ replying to @PlainCompass54

I would mostly agree except I understand that IGF-1 gains from tesamorelin drop off much faster than that, basically right away within a few days to a week.

ClearLantern81archiveJan 21
↳ replying to @IronThistle42 (opening post)

Several factors might account for the shift in growth factor readings, and the pattern isn't unusual once you consider the details. The medication boosts growth hormone release in pulses, yet the downstream marker relies a lot on how the liver responds, along with diet, insulin levels, swelling, and any recent strain or sickness. Carrying extra weight creates resistance to growth hormone. At the start of treatment while still carrying more mass, the liver didn't react strongly, keeping the marker low. Dropping dozens of pounds can restore better liver response, raising the marker even after pausing the medication. Tight calorie limits often hold the marker down temporarily, but once intake stabilizes and insulin handling improves thanks to the other agent, readings commonly climb again. The timing around the procedure added inflammatory strain that can dip the marker briefly, with a later upswing during healing. Test results themselves fluctuate quite a bit across visits because of meal timing, hour of day, minor sickness, or how binding proteins behave. The dual agonists don't lift the marker on their own, though better insulin action can nudge the liver toward higher output. In my situation the rise tracks with restored sensitivity after the big drop in weight, rather than any odd reaction to pausing the medication. Should the marker keep moving well above normal range without any secretagogues, tracking the direction over time matters more than one reading. I would run another test in roughly two to three months with the same setup, like morning fasted state at steady weight, before making much of it.

IronThistle42archiveJan 22
↳ replying to @ClearLantern81

I am grateful for the thorough explanation given. It is very helpful. I plan to use the recommendation and double-check everything in March.

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Unexpected IGF-1 Tesamorelin Lab · ZyraTrack Community