Possible side effects of arnica tincture include mild redness or irritation of the skin, according to Drugs.com. Some people may experience an allergic reaction to arnica tincture, signs of which include tightness in the chest, difficulty breathing, rash or hives. Swelling of the face, tongue, lips or mouth may also occur.
Some people may not experience any side effects when using arnica tincture, notes Drugs.com. If an allergic reaction occurs or if side effects become persistent or severe, a health-care professional should be contacted. Arnica tincture should only be used as prescribed, and the recommended dosage and duration of use should be followed unless specified by a physician. Arnica tincture should not be taken orally. If it is ingested, it is important to seek medical attention immediately.
It is possible to overdose on arnica tincture, notes Drugs.com. Possible signs of an overdose include pain or blood in the throat or mouth, bloody stools, diarrhea and changes in heart rate. Other signs of an overdose include vomiting, redness and pain. Pregnant or nursing women should speak to a doctor before using arnica tincture. Because some medicines may interact with arnica tincture, it is important to make sure a doctor or pharmacist is aware of any medications, supplements or other medicines being taken before using arnica tincture.