Hello. Thank you for writing to us at healthcaremagic
Dark underarms are most likely due to post-inflammatory hyperpigmentation/ PIH.
Post-inflammatory hyperpigmentation/ PIH is a non-specific reaction to any inflammatory insult to skin.
Possible causes for PIH in underarm region are either preceding/ recurrent fungal infections,
contact sensitivity to products and cosmetics e.g shaving creams, perfumes, deodorants Or chemical epilators etc.
The topical that you intend to use contains a
topical antifungal. It would only help if Pigmentation is due to underlying active fungal infection, not otherwise.
Your doctor would be able to confirm whether pigmentation has a fungal origin.
However, if not fungal in etiology, you may try a topical pigment reducing agent e.g
kojic acid, twice daily.
I suggest you to stop using all cosmetics and
hair removal products in this region.
You may use a trimmer instead.
Regards