When practiced by a qualified acupuncturist, acupuncture is extremely safe and most adverse events are minor. It is an all-natural, drug-free therapy, generally yielding no side effects just feelings of relaxation and well-being.
Following Clean Needle Technique protocols on handling and inserting needles properly further improves the safety of acupuncture. There is little danger of infection from acupuncture needles because they are sterile, used once, and then discarded. In this practice, only disposable needles sterilized by the manufacturer are used.
You might be interested to know about two very large German studies of acupuncture safety.* The studies reviewed approximately 2 million treatments and found that less than 9% of patients reported any adverse event and the most commonly reported events were bleeding or bruising at the area where the needle was inserted. Other adverse events associated with acupuncture included temporary discomfort at the site of needle insertion and even less common, feeling faint or experiencing fatigue.
*Witt C, Pach D, Brinkhaus B , et al. Safety of Acupuncture: Results of a Prospective Observational Study with 229,230 Patients and Introduction of a Medical Information and Consent Form Forsch Komplementmed. 2009;16:91–97. Melchart D, Weidenhammer W, Streng A, et al. Prospective Investigation of Adverse Effects of Acupuncture in 97 733 Patients. Arch Intern Med. 2004;164(1):104-105.