Serums for dark spots can be highly effective on black skin, depending on the active ingredients they contain and how consistently they are used. The key is to understand the underlying cause of the dark spots and to choose a serum that targets that specific issue.

Hyperpigmentation, or dark spots, on black skin is often caused by an overproduction of melanin, the pigment that gives skin its color. This can be triggered by various factors such as sun exposure, hormonal changes, or skin injuries, including acne.

Serums that contain ingredients like vitamin C, kojic acid, niacinamide, and licorice root extract can be particularly effective for treating dark spots on black skin.

1. Vitamin C: This potent antioxidant helps to lighten hyperpigmentation by inhibiting the enzyme tyrosinase, which is involved in melanin production. It also helps to protect the skin against damage from harmful free radicals and UV rays.

2. Kojic Acid: Derived from fungi, kojic acid also inhibits the production of melanin. It's a popular ingredient in skin-lightening products.

3. Niacinamide: Also known as vitamin B3, niacinamide can help to reduce the appearance of dark spots by inhibiting the transfer of melanin to the skin's surface.

4. Licorice Root Extract: This natural ingredient has been shown to lighten dark spots by dispersing melanin.

It's important to remember that while these ingredients can be effective, they're not a quick fix. It can take several weeks or even months of consistent use to see noticeable results. Also, it's crucial to use sun protection during the day, as sun exposure can exacerbate hyperpigmentation and counteract the effects of the serum.

Lastly, everyone's skin is unique, and what works for one person may not work for another. It's always a good idea to do a patch test first to ensure that you don't have an adverse reaction to the product. If you're unsure, consult with a dermatologist or a skincare expert.