known allergy to study compound (methyl nicotinate, vitamin B3, niacin)

skin conditions (e.g., dermatitis, psoriasis, eczema)

diagnosis or treatment for medical conditions that may affect normal vascular tone (e.g., diabetes, vasculitis, chronic hypertension, etc.)

Use of anti-inflammatory, antibiotic, or antihistamine medications within one month prior to study entry

Use of supplements like Omega 3 fatty acids within 3 months prior to study entry

Use of vitamin or nutritional supplement containing a dose of niacin/nicotinic acid above 50 mg/day at study entry

The Topical Niacin Skin Flush Test in First Episode Psychosis