💉 Injection Technique
The needle goes to a different depth for each kind of injection — that's the whole game. Pick a route and watch the angle and target layer change. Learning visual — not a substitute for supervised clinical training.
90°
Quick reference
| Route | Angle | Depth (target) | Typical gauge / length | Max volume |
|---|---|---|---|---|
| Intradermal (ID) | 5–15° | Dermis (just under skin — forms a bleb) | 26–27 G · 3/8–5/8″ | 0.1 mL |
| Subcutaneous (SubQ) | 45° (or 90° w/ short needle) | Fatty layer | 25–27 G · 5/8″ | ≤ 1 mL |
| Intramuscular (IM) | 90° | Muscle | 22–25 G · 1–1.5″ | 1–3 mL (≤1 deltoid) |
| Intravenous (IV) | 15–25° | Into a vein | 20–24 G catheter | per order |