Growth & hormones · ~3 min read
Tesamorelin: What It Is, How It Works & What the Research Shows
Overview
Tesamorelin is a stabilized analog of growth hormone-releasing hormone (GHRH) that stimulates the pituitary to release growth hormone and raises IGF-1. It is FDA-approved as Egrifta to reduce excess abdominal fat in people with HIV-associated lipodystrophy, where trials showed about 15–18% reductions in visceral fat. It has also been studied for reducing liver fat in fatty liver disease.
Why researchers study it
Visceral fat
FDA-approved as Egrifta; cut visceral fat about 15–18%.
Liver fat
Studied for reducing liver fat in fatty liver disease.
IGF-1
Raises IGF-1 through natural GH release.
How it works
Activates pituitary GHRH receptors to stimulate growth hormone release, with downstream effects on IGF-1 and metabolism. This is distinct from directly administering growth hormone.
Adamantane & the blood–brain barrier
Chemically attaching an adamantane group to a peptide can increase its lipid (fat) solubility. Researchers hypothesize that this modification may help certain compounds cross the tightly regulated blood–brain barrier. The effect depends on the specific modified molecule; greater lipid solubility alone does not establish brain delivery or clinical benefit. This does not apply automatically to the unmodified peptide and is not a reconstitution additive.
What the research shows
- A randomized trial evaluated reduction in visceral abdominal adipose tissue in people with HIV and excess abdominal fat.
- Growth hormone-releasing factor signaling and metabolic outcomes were studied; this is not evidence for general weight loss or bodybuilding.
Typical protocol
Reconstitute a 10 mg vial with 3 mL bacteriostatic water for 3.3333 mg/mL. Typical range: 0.5–2 mg 1x daily am/pm · 5 on 2 off or daily, 3–6 months · fasted.
Common stacks
- Tesamorelin + Ipamorelin — Pairs a GHRH analog with a ghrelin-receptor agonist for a larger GH pulse.
Potential benefits & side effects
Potential benefits
- Deeper, more restorative sleep
- Improved recovery from training
- Gradual improvements in body composition (more lean mass, less fat)
- Better skin, hair and overall vitality reported over longer cycles
Side effects
- Injection-site redness or irritation
- Water retention, tingling or numbness in hands
- Head rush, flushing or lightheadedness shortly after dosing
- Increased hunger (more with ghrelin-pathway peptides)
- Higher blood sugar at larger doses — monitor glucose and IGF-1
Lifestyle factors
- Sleep: aim for 7–9 hours; the largest natural GH pulse happens in deep sleep.
- Fasted dosing: dose away from meals — elevated insulin and carbs blunt the GH pulse.
- Training: pair with resistance training and real recovery days.
- Protein: keep protein intake adequate to support lean mass.
- Consistency: dose at the same time each day and rotate injection sites.