Subcutaneous peptide injection

The standard administration route for most research peptides — injected into the fat layer just under the skin, typically in the abdomen.

Why it matters

Subcutaneous injection delivers a peptide into the fatty layer beneath the skin, where it absorbs into circulation over minutes to hours depending on the molecule. Standard equipment is a 27–31 gauge insulin syringe with a short needle. Common injection sites are the abdomen (avoiding a 2-inch radius from the navel) and outer thighs.

In practice

Proper technique involves alcohol-wiping the site, pinching the skin to lift the fat layer, injecting at a 45–90 degree angle, and rotating sites to avoid lipohypertrophy. Disposal of sharps follows medical waste guidelines.

Common confusion

“Sub-Q injection is the same as IM injection” is wrong — subcutaneous targets the fat layer; intramuscular targets the underlying muscle, with different absorption kinetics.

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