Can homeopathy prevent premature greying?

With other aspects: "premature" graying generally means before age 35. Usually genetics is very much involved; pituitary, thyroid, and B12 problems can also contribute. At least 75 homeopathic remedies are known to include graying hair, but prescription is based on whole-being assessment. To find the best remedy, a good homeopath would explore the deeper effects of the graying on you as well as other things.

Depends!: As a single complaint, difficult to say, but within a constellation of symptoms suggesting a constitutional prescription then healing is probable!