What is the recommended volume for an intramuscular (IM) injection in the deltoid muscle for a typical adult patient with no significant medical history?

Deltoid Intramuscular Injection Volume

For a typical adult with no significant medical history, inject up to 1 mL in the deltoid muscle, though volumes up to 2 mL are generally acceptable if necessary. 1

Standard Volume Guidelines

The deltoid muscle in adults has limited capacity compared to larger muscle groups:

• Maximum recommended volume: 1-2 mL for routine deltoid injections in adults 1
• The deltoid is preferred for routine intramuscular vaccinations, which typically involve volumes of 0.5-1 mL 2, 1
• For larger volumes (>2 mL), the anterolateral thigh or ventrogluteal site should be used instead, as these sites have greater muscle mass 2, 3

Proper Injection Technique for Deltoid

Needle Specifications

• Needle length: 1 to 1½ inches (25-38 mm) 2, 1, 4
• Needle gauge: 22-25 gauge 2, 1
• Insert at a 90-degree angle perpendicular to the skin 1

Site Selection Within the Deltoid

• The optimal injection site is the middle third of the deltoid muscle 5
• More specifically, inject 4 cm distal to the posterolateral corner of the acromion to maximize successful intramuscular delivery while minimizing risk to the axillary nerve 6
• This site is more posterior and inferior than many practitioners currently use 6

Needle Length Selection Based on Patient Characteristics

Weight-Based Approach

• Patients <60 kg: Use 0.625-inch (16 mm) needle 6, 7
• Patients 60-90 kg (females) or 60-118 kg (males): Use 1-inch (25 mm) needle 6, 7
• Patients >90 kg (females) or >118 kg (males): Use 1.5-inch (38 mm) needle 6, 7

Sex-Specific Considerations

Women have significantly thicker subcutaneous tissue in the deltoid region compared to men at the same BMI 8, 7:

• Women with BMI >35: Require a 32 mm (1.25-inch) needle to ensure intramuscular delivery 8
• Men across most weight ranges: A 25 mm (1-inch) needle achieves adequate muscle penetration 7

Critical Pitfalls to Avoid

• Using inadequate needle length results in subcutaneous rather than intramuscular delivery, reducing medication efficacy and potentially increasing local adverse reactions 1, 4
• Injecting volumes >2 mL in the deltoid risks inadequate absorption and increased local reactions due to limited muscle mass 2
• Injecting too superiorly or anteriorly increases risk of overpenetration and potential nerve injury 6
• Never use the buttock for routine injections due to sciatic nerve injury risk and decreased immunogenicity 1, 4

Multiple Injections in Same Visit

When administering multiple injections:

• Separate injection sites by >1 inch (2.5 cm) if using the same limb 2, 1, 3
• Use both deltoids and the anterolateral thigh when three or more injections are needed 3
• Document the location of each injection in the medical record 2, 3