From my experience, incorporating glycolic acid from The Ordinary into your underarm care routine can make a significant difference in reducing darkness and discoloration. Glycolic acid is an alpha hydroxy acid (AHA) that gently exfoliates the skin, removing dead skin cells and promoting cell turnover, which is key to achieving brighter underarms. To start, ensure your underarms are clean and dry before applying the glycolic acid solution. I found it’s best to use it at night to avoid sun sensitivity and always follow up with sunscreen during the day if your underarms are exposed. Consistency is crucial; applying it a few times a week gradually helps even out the skin tone without irritation. During the first few weeks, some mild tingling or redness can occur, which is normal as your skin adjusts. Make sure to moisturize the area well, as glycolic acid can sometimes dry the skin. Additionally, avoid shaving immediately after application to prevent irritation. Alongside glycolic acid, I combined gentle exfoliation and maintaining proper hygiene, which helped prevent the buildup of dead skin and bacteria that can contribute to discoloration. Watching progress weekly, as inspired by the routine shared in the series, allowed me to track changes and stay motivated. Overall, glycolic acid from The Ordinary has provided a budget-friendly, effective option for treating dark underarms. Patience and a gentle approach are key, and over time you’ll notice smoother, brighter skin with reduced dark patches and stains.