P21 vs Gonadorelin
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
P21
P21 is a synthetic peptide derived from Cerebrolysin, specifically designed to mimic the neurotrophic effects of the parent compound. It promotes neurogenesis and has shown cognitive-enhancing properties in research.
Full details →Gonadorelin
Gonadorelin is a synthetic form of gonadotropin-releasing hormone (GnRH). It stimulates the pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), supporting natural hormone production.
Full details →Side-by-Side Comparison
| Aspect | P21 | Gonadorelin |
|---|---|---|
| Mechanism | Inhibits glycogen synthase kinase-3β (GSK-3β) and activates CREB signaling pathway. This promotes BDNF expression, neurogenesis in the hippocampus, and synaptic plasticity. | Binds to GnRH receptors in the pituitary gland, triggering pulsatile release of LH and FSH. This stimulates testicular or ovarian function and natural sex hormone production. |
| Typical Dosage | Research protocols typically use 1-5mg administered intranasally or subcutaneously. Often used in cycles of 2-4 weeks. | Men: 100-200mcg subcutaneously 2-3 times daily. Women (fertility): Per clinical protocol. HRT support: Often combined with other therapies. |
| Administration | Can be administered intranasally for direct CNS access or subcutaneously. Best used cyclically rather than continuously. | Subcutaneous injection. Pulsatile administration mimics natural GnRH release patterns. Often used during or after testosterone therapy. |
| Side Effects | Limited data. Reported effects include mild headache, temporary brain fog during initial use, and fatigue. | Headache, flushing, injection site reactions. In women may cause ovarian hyperstimulation. Generally well-tolerated. |
| Best For |