 Buckwheat contains fluorescent phototoxic fagopyrins.Seeds, flour, and teas are generally safe when consumed in normal amounts, but fagopyrism can appear in people with diets based on high consumption of buckwheat sprouts, and particularly flowers or fagopyrin-rich buckwheat extracts.Symptoms of fagopyrism in humans may include skin inflammation in sunlight-exposed areas, cold sensitivity, and tingling or numbness in the hands.