How does IGF-1 track your response?
Sermorelin and tesamorelin both work by prompting your own pituitary gland to release more growth hormone, and the liver answers that extra growth hormone by making more IGF-1. Because growth hormone itself pulses up and down through the day, MedlinePlus points to IGF-1 as the more stable and reliable way to track it. A rise in IGF-1 is the clearest lab sign that the peptide is doing what it is supposed to do.
The tesamorelin (EGRIFTA SV) label describes this directly: tesamorelin stimulates growth hormone secretion and then raises IGF-1 and its main carrier protein, without meaningful changes in other pituitary hormones in its trials. Sermorelin, once approved as Geref and now compounded, works through the same growth-hormone-releasing pathway.
That makes the before-and-after comparison the heart of monitoring. A baseline IGF-1 drawn before the first dose, and a recheck once you are on a steady routine, show how far you moved and where you now sit in your age range. Our IGF-1 blood test for men page explains those age-adjusted ranges.
Where is the ceiling?
The ceiling is the top of the normal IGF-1 range for your age. Neither peptide has an official numeric target for healthy men, so clinicians borrow the logic used with growth hormone itself. The Genotropin (somatropin) label tells clinicians treating adults with growth hormone to lower the dose when IGF-1 rises above the age- and sex-specific normal range, and to use those adjusted IGF-1 values to guide dosing.
Tesamorelin’s label is more specific about how often overshooting happens. In its trials, 47% of patients had IGF-1 more than 2 standard deviation scores above the mean after 26 weeks, and 36% were above 3, with high values appearing as early as week 13. The label advises monitoring IGF-1 and considering discontinuation when levels stay elevated, for example above 3, particularly if the treatment is not clearly working.
A standard deviation score of 0 sits in the middle for your age, and about +2 marks the upper edge of the normal band. In practice:
| IGF-1 on treatment | What it suggests | Typical response |
|---|---|---|
| Little change from baseline | Weak response or a dosing problem | Check adherence, timing and technique, then recheck |
| Risen, within the age range | Responding as intended | Continue and monitor |
| At the top of the age range | Near the ceiling | Hold the dose; avoid pushing higher |
| Above the age range, especially if persistent | Overshoot | Lower the dose or stop |
What does a flat rise mean?
A flat IGF-1 means the peptide is not raising growth hormone activity enough to register, and the first step is to look for practical reasons before blaming the peptide. Common ones include missed doses, injecting at inconsistent times, mixing or storage problems that weaken the product, or a draw taken too soon after starting.
Some reasons are biological. These peptides depend on a pituitary that can respond, which is why the tesamorelin label rules it out for men whose pituitary function has been disrupted by surgery, tumors, head radiation or head trauma. Product quality matters as well: sermorelin is compounded, and the FDA notes that compounded drugs are not reviewed by the agency for safety, effectiveness or quality before they are sold.
If technique and adherence check out and IGF-1 still has not moved, your provider may adjust the plan or recommend stopping. Our guide on storing peptides and injectables covers the handling side, and our answer on how long peptides take to work sets realistic timelines.
What does an excessive rise change?
An IGF-1 above your age range usually means the dose comes down or treatment pauses. The tesamorelin label notes that the long-term effects of raised IGF-1 are unknown, and it lists fluid retention as a related side effect, showing up as swelling, joint pain or carpal tunnel symptoms such as numb, tingling fingers.
A high IGF-1 is also a prompt to check blood sugar, since growth hormone can reduce insulin sensitivity. The tesamorelin label reports more new diabetes-range A1c results on treatment than on placebo, and the Genotropin label warns that growth hormone can unmask impaired glucose tolerance. Our answer on peptide injection side effects lists what to report between visits.
Why is IGF-1 not the only measure?
IGF-1 shows that the peptide is acting, but it does not show that you are getting the result you came for. Tesamorelin’s approved use is reducing excess abdominal fat in people with HIV-associated lipodystrophy, and its label suggests weighing persistent IGF-1 elevation against how clearly the treatment is working. Body composition, waist, sleep, recovery and how you feel all count alongside the number.
Glucose and A1c stay on the follow-up list too. Our page on blood work before peptide therapy explains why they are part of the baseline, and our tesamorelin page covers that option’s FDA status.
How Ultimate Male monitors IGF-1
Men who start sermorelin or tesamorelin at Ultimate Male have follow-up labs and a check-in at six to eight weeks, then adjustments as they respond. Draws happen on site at San Gabriel or Downey, ideally at the same lab and time of day as the baseline, with results in 24 to 48 hours.
Your provider sets and changes the dose; the IGF-1 result, your glucose and how you are feeling all feed that decision. For a sense of how ongoing labs affect the overall budget, see our page on sermorelin cost.
