Arnica Montana is an herb that is often taken as a supplement to prevent or treat bruising or swelling. Doctors will often recommend it to patients undergoing surgery or cosmetic procedures.  It is most commonly sold as a topical gel or an oral capsule.  The only safe form of the capsule is the homeopathic version.

What is a homeopathic remedy?  It is a diluted preparation that actually contains very little of the original substance.  In fact, it is often so "watered down"  that the herb or substance in question is not detectable in the remedy.  In many ways, this idea is contrary to the tenants of traditional western medicine. 

The good news is that homeopathic treatments are generally quite safe, since they often don't contain much of anything.  The bad news is that there is little evidence to support that they work.  

Dr. Kotlus published an article in this month's Ophthalmic Plastic and Reconstructive Surgery Journal that evaluated homeopathic Arnica after eyelid surgery (blepharoplasty).  Homeopathic arnica pills were no better than placebo at preventing bruising or improving recovery after surgery.  

So if you are thinking about taking Arnica around the time of your eyelid lift, it probably won't hurt you, but it won't help either.