What is the best scar removal cream for black spots on under arms? (Photo)

Understanding the process by which scar revision is recommended is relatively easy. We first characterize the scars physical and physiologic features such as redness, inflammation, growth, thickness, and then identify lasers and injection treatments vs. surgery that work best for that particular scar. 
Scar revision requires a disciplined approach to address the different characteristics of scars including texture, color, level of inflammation, vascularity, and hypertrophy. Our office specializes in scar revision because we have both cosmetic dermatologists, plastic surgeons, and general surgeons within our center. The ideal scar treatment is combination therapy that incorporates vascular lasers, microfractional RF and laser, microneedling, Micro-ionization ablation, PRP, topical growth serums and polysiloxane topical gels, and surgery if indicated. 
I recommend Melarase PM for patients that have dark and discolored scars and Plato’s Scar Serum twice daily for all new and hypertrophic scars prior to any treatment. 
Best, 
Dr. Karamanoukian
Realself100 Surgeon

Thank you for your question and photograph. It's difficult to evaluate and assess your skin through this type of forum. There are some medical conditions that can cause dark discoloration to the underarms, so treatment options will vary. I highly recommend you consult with a board certified dermatologist to have your skin evaluated and to discuss treatment options that best suits your skin. Take care and good luck.