Rescue Remedy, a popular over-the-counter anxiety treatment made from highly distilled "flower essences," generally causes no side effects beyond placebo. According to a systematic review by Edzar Ernst, Rescue Remedy contains no pharmacologically active herbal ingredients. An additional review published in "BMC Complementary and Alternative Medicine" noted that Rescue Remedy, like other homeopathic-strength preparations, is generally considered safe for pregnant women, infants, children and people with medical conditions. However, peach brandy, used in small amounts as a preservative in Bach's Rescue Remedy, may cause adverse effects.

Risk to Alcoholics

"BMC Complementary and Alternative Medicine" notes that alcohol preservatives in Rescue Remedy may pose a threat to recovering alcoholics. Trace amounts of peach brandy, used as a preservative, may trigger strong cravings for other forms of alcohol.

Headache

According to "BMC Complementary and Alternative Medicine," two people involved in Rescue Remedy clinical trials developed headaches; one withdrew from the study because of this perceived side effect. Among 468 patients reviewed in the trial, only four Rescue Remedy users reported adverse effects; three people taking a placebo also experienced side effects.

Skin Rash

One person taking Bach Rescue Remedy developed a skin rash, according to BMC's systematic review. This may have been a reaction to contaminants, an allergy to compounds in peach brandy or an unrelated situational reaction.

Psychological Dependence

Flower essences can not cause addiction, according to the Bach Centre. However, people may experience psychological dependence to Rescue Remedy after using it extensively as a calming ritual or treatment for anxiety.