Pegvisomant
Also known as: Somavert, B2036-PEG
A growth hormone receptor antagonist, FDA-approved as Somavert (2003) for acromegaly not controlled by surgery or radiation. Prescription medication.
Last updated
Mechanism of Action
Pegvisomant is a modified, PEGylated growth hormone molecule. It binds the GH receptor but blocks the functional receptor dimerization needed for signaling, so it prevents GH action rather than reducing GH secretion. The result is lower IGF-1 production; serum GH levels actually rise during treatment, so response is tracked with IGF-1. PEGylation slows clearance and reduces immunogenicity.
- Half-life
- ~6 days
- Administration Routes
- Subcutaneous
- Research Status
- Clinical
Reported Benefits
- Normalizes IGF-1 in most patients with acromegaly in pivotal trials
- Improves acromegaly symptoms such as soft-tissue swelling and sweating
- Used alone or combined with somatostatin analogs in resistant disease
Potential Side Effects
- Elevated liver enzymes; liver tests required at baseline and during therapy
- Injection-site reactions and lipohypertrophy
- Possible growth of the underlying pituitary tumor; MRI monitoring advised
- Hypoglycemia in patients with diabetes on insulin or oral agents
- Flu-like symptoms, headache
Common Dosing
Labeled dosing begins with a subcutaneous loading dose followed by daily injections, adjusted in small steps based on IGF-1 levels every 4-6 weeks. Dosing is set and supervised by the prescribing endocrinologist.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- Hypersensitivity to pegvisomant or components
- Use caution with baseline liver test elevations above 3x the upper limit of normal (work-up required first)
Octreotide
A somatostatin analog for acromegaly and neuroendocrine tumor symptoms. FDA-approved as Sandostatin since 1988. Prescription medication.
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A long-acting somatostatin analog for acromegaly and neuroendocrine tumors. FDA-approved as Somatuline Depot since 2007. Prescription medication.