Retinol, a derivative of vitamin A, is a popular ingredient in skincare due to its ability to accelerate skin renewal and reduce the appearance of wrinkles, fine lines, and age spots. It is a potent tool against hyperpigmentation, including dark spots, as it promotes cell turnover, allowing new skin cells to come to the surface and replace the older, pigmented ones. Here are some of the best retinol serums to consider for combating dark spots:

1. "SkinCeuticals Retinol 1.0": This high-concentration retinol serum is designed for problematic and sun-damaged skin that has become accustomed to retinol treatments. It helps to reduce the appearance of dark spots and fine lines.

2. "Paula's Choice 1% Retinol Booster": This lightweight serum can be used alone or added to your moisturizer. It's formulated with a controlled-release delivery system to slowly release retinol, reducing the chance of irritation.

3. "Drunk Elephant A-Passioni Retinol Cream": This cream is packed with 1% retinol and supportive peptides to restore bounce, resilience, and clarity to skin while also helping to even out tone and texture.

4. "Murad Retinol Youth Renewal Serum": This serum uses a fast-acting retinoid, a time-released retinol, and a retinol booster to quickly and visibly minimize lines, wrinkles, and smooth texture.

5. "La Roche-Posay Redermic R Anti-Aging Retinol Serum": This is an excellent option for sensitive skin. It contains a gentle dose of retinol along with lipo-hydroxy acid, a gentle exfoliant that helps the retinol penetrate the skin more effectively.

6. "Neutrogena Rapid Wrinkle Repair Serum": This budget-friendly option contains a stabilized retinol compound along with hyaluronic acid, which can help hydrate and plump the skin.

Remember, retinol can make your skin more sensitive to the sun, so it's crucial to use a broad-spectrum sunscreen during the day. Also, it's best to introduce retinol slowly into your skincare routine to minimize potential irritation. Start with a lower concentration and gradually increase as your skin becomes more accustomed to it.