How peptides are taken.
“Delivery method” is how a peptide gets into the body — and it hugely affects how much actually works (bioavailability). Here's a plain-language guide to the main routes.
Subcutaneous injection (SubQ)
A tiny insulin needle delivers the peptide into the fat layer just under the skin (belly, thigh). Simple, low-discomfort and the default for most research peptides.
- Bioavailability:
- High and consistent
- Often seen with:
- BPC-157, Ipamorelin, Semaglutide, Tesamorelin
Intramuscular injection (IM)
Injected into muscle with a longer needle. Used for certain compounds or larger volumes; slightly faster uptake for some peptides.
- Bioavailability:
- High
- Often seen with:
- Some GH peptides, longer-ester compounds
Nasal spray (Intranasal)
Sprayed into the nose; convenient and needle-free. Useful for peptides targeting the brain, though absorption is lower and more variable than injection.
- Bioavailability:
- Low–moderate, variable
- Often seen with:
- Selank, Semax, PT-141, Oxytocin
Oral (capsule / tablet)
Swallowed like a supplement. Most peptides are broken down in the gut, so oral forms need special formulation or absorption enhancers to work at all.
- Bioavailability:
- Very low (unless specially formulated)
- Often seen with:
- Oral semaglutide, MK-677
Sublingual / buccal
Drops or troches held under the tongue or in the cheek, absorbing through the lining and bypassing some gut breakdown. A middle ground for needle-averse research.
- Bioavailability:
- Low–moderate
- Often seen with:
- Some blends and troche formulations
Topical / transdermal
Creams and serums applied to the skin for local effect — common in cosmetic and skin-repair research rather than systemic use.
- Bioavailability:
- Local; minimal systemic
- Often seen with:
- GHK-Cu serum, Argireline
A note on reconstitution & storage
Most injectable peptides ship as a freeze-dried (lyophilized) powder and are mixed with bacteriostatic water before use. Reconstituted peptides are generally kept refrigerated and protected from light. Always follow proper sterile technique and the guidance applicable in your region.
💬 Community notes
Share your experience or ask a question. For research discussion only — not medical advice.