Injection sites vary by type (subcutaneous SQ or intramuscular IM), with common SQ areas including the abdomen (away from navel), thighs, and upper arms, while IM sites are typically the deltoid, How to Take Glutathione Effectively: Best Forms, Timing & Tips Which Area of the Body Is Best to Inject Glutathione? Glutathione IM Shots: Advanced Antioxidant & Immune Support: Irina Gressel, MD: Family Medicine