Research Tools

Injection Site Diagram

Interactive body diagram with needle length, angle, volume limits, and rotation advice for each injection zone. Click any highlighted area to view technique details.

Front

Back

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Zones

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Click any highlighted area on the diagram or a zone button to see needle length, angle, volume limits, technique, and common mistakes.

SC vs IM: Key Differences

Most research peptides are administered subcutaneously (SC). Intramuscular (IM) is used for larger volumes or compounds requiring faster peak absorption.

Subcutaneous (SC)

•Inject into the fatty layer between skin and muscle

•29–31G × 4–6 mm insulin-type needle

•45–90° angle depending on tissue thickness

•Volume: up to 1 mL per injection site

•Slower, sustained absorption — ideal for depot formation

•Used by: BPC-157, TB-500, GHK-Cu, semaglutide, tirzepatide, ipamorelin, most peptides

Intramuscular (IM)

•Inject directly into muscle tissue

•22–25G × 16–38 mm needle (length varies by site and tissue depth)

•90° angle to skin surface

•Volume: deltoid ≤1 mL; vastus lateralis ≤2 mL; ventrogluteal ≤3 mL

•Faster absorption due to rich muscle vasculature

•Used for: large-volume injections (NAD+), some TB-500 protocols, or when SC volume limit is exceeded

Rotation Strategy

8-Site Rotation Protocol

For compounds requiring daily injection (BPC-157, ipamorelin, sermorelin, NAD+), an 8-site rotation allows each site 7 days of recovery before re-use.

1.Right Abdomen
2.Right Anterior Thigh
3.Right Deltoid (if IM and low-volume)
4.Right Ventrogluteal (if IM)
5.Left Abdomen
6.Left Anterior Thigh
7.Left Deltoid
8.Left Ventrogluteal

Needle Size Reference

Gauge	Length	Route	Best For	Flow Rate
29–31G	4–6 mm	SC — Subcutaneous	All peptides, daily SC injections (BPC-157, ipamorelin, semaglutide)	Slow — ideal for SC depot
27–28G	6–12 mm	SC — Subcutaneous	Slightly larger SC volumes (0.5–1 mL), subcutaneous belly fat	Moderate
25–26G	16 mm (⅝")	IM — Intramuscular	Deltoid IM, thin patients, standard IM	Moderate
23–24G	25 mm (1")	IM — Intramuscular	Thigh IM (vastus lateralis), average tissue depth	Moderate–fast
21–22G	38 mm (1.5")	IM — Intramuscular	Ventrogluteal IM, large volume injections (NAD+), larger subjects	Fast

Research Use Only — Disclaimer

This diagram is intended for qualified researchers and educational reference only. All information is provided for in vitro / in vivo preclinical research study design. This tool does not constitute medical advice, clinical guidance, or instruction for human self-administration. Nexphoria products are sold strictly for laboratory research purposes and are not approved for human use, diagnosis, treatment, or prevention of any disease or condition.

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