Feverfew side-effects

Complaints of side-effects by feverfew users have been limited. Mouth ulcers have been suggested to be the most common side-effect which seems to be a systemic effect [2, pp. 79,80]. A survey carried out among 300 feverfew users revealed that 18% experienced side-effects and 11.3% of users reported mouth ulcers [2, pp. 77-80]. In a different analysis of 164 patients who had stopped taking feverfew, 21 % did so because of side-effects [2, pp. 82,83]. A prospective clinical trial [5] carried out to assess the efficacy of feverfew in a controlled way reported that mouth ulcers were more common during the placebo treatment. 

Two clinical trials of the effects of feverfew in migraine have shown beneficial effects by feverfew but no clinical benefit could be demonstrated for arthritis. There have been suggestions that platelets and neutrophils may play a role in migraine and arthritis respectively, although no study has clearly established a link between any in vitro effects of feverfew and possible clinical benefits. Few side-effects have been noted and although the components of feverfew have been shown to have cytotoxic properties under some experimental conditions, the relevance of this to the clinical situation is not clear. 

Mouth ulcers and gastrointestinal upset are the most common side effects associated with the use of feverfew. In a survey of 300 feverfew users, 11.3% reported mouth ulcers. External contact dermatitis may also occur. A rebound syndrome, consisting of nervousness, tension headache, insomnia, and joint stiffness has been reported in some patients who abruptly discontinued using feverfew. 

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