As with any potent active, sideeffect potential exists (especially with retinoid: irritation, sun sensitivity)
Some users hit the copper uglies phase here, where skin briefly looks worse before it gets better

Major Ingredients Water, Triethylhexanoin, Hydrogenated Poly(C6-14 Olefin), Butylene Glycol, Niacinamide, Methylpropanediol, 1,2-Hexanediol, Phenyl Trimethicone, Diethoxyethyl Succinate, Polyglyceryl-10 Myristate, Borago Officinalis Extract, Centaurea Cyanus Flower Extract, Chamomilla Recutita (Matricaria) Flower/Leaf Extract, Lavandula Angustifolia (Lavender) Flower Water, Hyacinthus Orientalis (Hyacinth) Extract, Salvia Sclarea (Clary) Extract, Ethylhexylglycerin, Hibiscus Esculentus Fruit Extract, Corchorus Olitorius Leaf Extract, Carum Petroselinum (Parsley) Extract, Hexyl Cinnamal, Limonene, Linalool, Fragrance, Hippophae Rhamnoides Oil, Allantoin, Hydrogenated Lecithin, Sodium Gluconate, Glutathione, Adenosine, Cellulose Gum, Melia Azadirachta Leaf Extract, Melia Azadirachta Flower Extract, Curcuma Longa (Turmeric) Root Extract, Ocimum Sanctum Leaf Extract, Corallina Officinalis Extract, Biotin, Biotinoyl Tripeptide-1, Acetyl Hexapeptide-8, Tripeptide-1, Tripeptide-3, Myristoyl Pentapeptide-17, Hexapeptide-9, Gluconolactone, Alpha-Arbutin, Thioctic Acid Ingredients subject to change at manufacturer's discretion

Legal and Regulatory Considerations In the United States, the regulatory status of BPC-157 is complex
4.1 Glutathione Dosage for Skin Whitening (Oral) For the first 3 months, you can take approximately 1000mg-2000mg of Glutathione, then reduce it to 500mg per day