What is the optimal injection site rotation for a weekly semaglutide (Wegovy) shot in an adult patient with a body mass index (BMI) of 30 or higher, or 27 or higher with at least one weight-related condition, and no significant medical history?

Optimal Injection Site Rotation for Weekly Wegovy (Semaglutide) Shots

Rotate Wegovy injections systematically within one anatomical region each week (abdomen, thigh, buttock, or upper arm), rather than switching between different body regions with each injection, to minimize day-to-day variability in absorption. 1

Approved Injection Sites

Wegovy can be injected into four anatomical regions 1:

• Abdomen: 2 adult fingerbreadths (approximately 5 cm) away from the umbilicus, avoiding a circle with 2-inch radius around the navel 1
• Thigh: Upper third anterior lateral aspect of both thighs 1
• Buttock: Posterior lateral aspect of both upper buttocks and flanks 1
• Upper arm: Middle third posterior aspect of the upper arm 1

The Critical Rotation Strategy

The key principle is to rotate systematically WITHIN one anatomical area rather than jumping between different body regions each week. 1 This approach is superior because:

• Absorption rates differ significantly between sites: the abdomen has the fastest absorption rate, followed by arms, thighs, and buttocks 1
• Rotating within one area decreases variability in absorption from day to day, leading to more predictable drug levels and therapeutic effects 1
• Switching between different anatomical regions with each injection creates unpredictable absorption patterns that can affect glycemic control and treatment efficacy 1

Practical Weekly Rotation Protocol

For a patient on weekly Wegovy injections, implement this systematic approach 1:

Week 1-4: Use the abdomen exclusively

• Inject 2 fingerbreadths away from umbilicus
• Move to a different quadrant each week (upper right → upper left → lower right → lower left)
• Maintain at least 1 inch spacing between injection sites

Week 5-8: Switch to thighs

• Use upper third anterior lateral aspect
• Alternate between right and left thigh weekly
• Move injection site within the thigh region each time

Week 9-12: Move to buttocks

• Use posterior lateral aspect
• Alternate between right and left buttock weekly
• Rotate within the available area

Week 13-16: Use upper arms

• Middle third posterior aspect
• Alternate between right and left arm weekly
• May require assistance for proper injection technique

Then repeat the cycle starting at Week 17

Injection Technique Specifications

Use 4-mm pen needles inserted at 90 degrees for all adults regardless of age, sex, ethnicity, or BMI. 1 This recommendation applies universally to semaglutide and other GLP-1 receptor agonists 1.

• No skin pinching is required when using 4-mm needles at 90 degrees for most adults 1
• If using needle lengths >4 mm, a correctly lifted skinfold must be used to avoid intramuscular injection 1
• Inject into healthy subcutaneous fat tissue, avoiding intradermal and intramuscular spaces 1

Critical Areas to Avoid

Never inject into areas with lipohypertrophy (LH), scars, or bony prominences. 1 Lipohypertrophy appears as soft, smooth raised areas several centimeters in breadth and contributes to 1:

• Erratic insulin absorption (applies to all subcutaneous medications including GLP-1 agonists)
• Increased glycemic variability
• Unexplained hypoglycemic episodes

Avoid bony prominences by 1-2 adult fingerbreadths to ensure proper subcutaneous delivery 1.

Monitoring and Site Inspection

Examine injection sites at every regular visit, or at least annually, to screen for lipohypertrophy and other complications. 1 Patients should be taught to:

• Self-inspect sites regularly 1
• Distinguish healthy from unhealthy tissue 1
• Recognize lipohypertrophy as raised, soft areas 1
• Immediately stop using affected areas if lipohypertrophy develops 1

Administration Timing and Flexibility

Administer Wegovy once weekly at any time of day, with or without meals. 2, 3 The day of weekly administration can be changed if necessary, as long as the time between two doses is at least 2 days (48 hours) 2.

Common Pitfalls to Avoid

• Don't rotate to a completely different body region each week – this creates absorption variability 1
• Don't inject too close to previous injection sites – maintain at least 1 inch spacing to prevent lipohypertrophy 1, 4
• Don't inject into the same exact spot repeatedly – even within one region, move the injection site 1
• Don't ignore developing lipohypertrophy – mark borders and avoid these areas completely 1
• Don't use needles longer than 4 mm without proper skinfold technique – this risks intramuscular injection 1

Why This Rotation Pattern Matters for Wegovy Specifically

While the evidence base for injection site rotation comes primarily from insulin delivery guidelines 1, these recommendations explicitly apply to GLP-1 receptor agonists including semaglutide 1. The Mayo Clinic Proceedings guidelines specifically state that "insulin and glucagon-like peptide-1 receptor agonists must be deposited into healthy subcutaneous fat tissue" with proper rotation 1.

The systematic within-region rotation approach optimizes 1, 2:

• Predictable drug absorption and therapeutic effect
• Prevention of lipohypertrophy development
• Sustained efficacy of the 2.4 mg weekly dose for weight management
• Minimization of injection site complications