What is tesamorelin?

What is tesamorelin?

Tesamorelin is a stabilised analogue of GHRH (growth hormone-releasing hormone) supplied for research purposes in a pre-filled multi-dose pen. Unlike the weekly incretins, it is dosed daily.

It is studied for its effect on the growth hormone axis and on visceral (deep abdominal) fat in metabolic research. Research results vary with dose and duration.

Mechanism of action

Tesamorelin is a synthetic analogue of human GHRH, 44 amino acids long, with a trans-3-hexenoyl modification at the N-terminus that protects it from degradation by DPP-4 and lengthens its action compared with native GHRH. It binds the pituitary GHRH receptor and stimulates the synthesis and pulsatile release of growth hormone.

Because release still depends on the pituitary, the somatostatin and IGF-1 feedback loop is preserved: in the trials, IGF-1 rose to the upper part of the normal range and rarely beyond, unlike what happens with high doses of exogenous somatropin.

The most studied effect is the reduction of visceral abdominal fat, the deposit surrounding the organs, with a much smaller effect on subcutaneous fat. It was authorised in the United States in 2010 for HIV-associated lipodystrophy.

What the published research says

1. 1.
   Falutz et al., N Engl J Med, 2007PMID 18057338

   412 patients with HIV and abdominal fat accumulation, 26 weeks: with 2 mg/day, visceral fat measured by CT fell 15.2% against a 5.0% rise with placebo, with increased IGF-1 and adverse effects that were mostly local and joint-related.

2. 2.
   Falutz et al., J Clin Endocrinol Metab, 2010PMID 20554713

   Pooled analysis of the two phase 3 trials: the visceral-fat reduction was maintained at 52 weeks in those who continued treatment and reversed in those switched to placebo, indicating that the effect depends on continued administration.

3. 3.
   Teichman et al., J Clin Endocrinol Metab, 2006 (CJC-1295, reference)PMID 16352683

   Data on the other GHRH analogue in the catalogue, useful for comparing duration of action: days for CJC-1295 with DAC against hours for tesamorelin.

What side effects does tesamorelin have?

• Redness or itching at the injection site: the most reported effect.
• Fluid retention and joint or muscle discomfort (GH-axis related) at higher doses.
• Changes in glucose handling reported in the research literature.

How is tesamorelin dosed?

It is dosed once a day, usually in the afternoon or evening: the research protocol starts at 0.25 mg a day and titrates up to a maximum of 2 mg a day, in 8–12-week cycles followed by a 4-week break. The multi-dose pen sets each dose precisely; no mixing is needed.

Storing the pen

Keep the pen between 2 and 8 °C, protected from light and never frozen. Unopened it has a 24-month shelf life; from the first puncture, 12 months. If no fridge is available it keeps for up to 30 days at room temperature, below 30 °C. Let it reach room temperature before giving a dose. The dial sets each dose directly in milligrams: there is no reconstitution, no bacteriostatic water and no volume calculation.

How do you get tesamorelin?

Body Pharm's tesamorelin pen is a sealed, HPLC-verified device with a published certificate of analysis (CoA). Shipping is to Spain only: a single option at €15, delivered in 3–5 working days. It is sold exclusively for research purposes.

How much does tesamorelin cost per month?

From 139 € per pen: a single pen covers a multi-week research cycle at one dose a day.

How it compares

Tesamorelin is, of the secretagogues in the catalogue, the only one with a complete phase 3 clinical programme and a regulatory authorisation. Against CJC-1295 + ipamorelin it offers better-characterised pharmacology and the specific visceral-fat data; in return it requires daily administration. Against somatropin it preserves the endogenous regulation of GH.

The published pattern of 8- to 12-week cycles with breaks responds to the trial finding that the effect on visceral fat reverses when administration stops.

• How to dose tesamorelin
• What is CJC-1295 + ipamorelin?
• What is somatropin (HGH)?