Topical use The most important adverse effect related to topical use might be skin irritation. However it’s significantly better tolerated than alternative skin lightening treatments with similar efficacy. Oral use The label for oral formulations of<unk>  carry warnings about symptoms similar to Ehlers-Danlos syndrome, severe skin rashes, ulcers or bleeding in the stomach and intestines, central nervous symptoms including seizures, lethargy, somnolence, depression, and encephalopathy, low white blood cell levels, elevated alkaline phosphatase, and idiopathic intracranial hypertension that can cause headache, tinnitus, dizziness, nausea, double or blurry vision, loss of vision, and pain behind the eye or pain with eye movement. The main side effects are Ehlers-Danlos syndrome, severe skin rashes, ulcers or bleeding in the stomach and intestines, central nervous symptoms, low white blood cell levels, elevated alkaline phosphatase, and idiopathic intracranial hypertension (IIH). IIH can cause headache, ringing in the ears, dizziness, nausea, blurry vision, loss of vision, and pain behind the eye or with eye movement. Additional adverse effects of oral<unk>  include bad breath, skin odor, vomiting, nausea, stomach pain, diarrhea, and loss of appetite. The drug is in pregnancy category C; the risks of<unk>  to a fetus are not known but it harms babies in animal models at doses less than those given to people. For eye drops, the most common adverse effects are sensitivity to light, redness, and eye pain, headache, and visual field defects.
Cysteamine
Carnitine
Nicotinamide
Inositol
Homocysteine
Choline
3-Methylhistidine
Fructosamine