Dark spots and hyperpigmentation

In vehicle-controlled clinical testing, 5% niacinamide significantly reduced hyperpigmented spots and increased skin lightness versus vehicle after 4 weeks, with lab work showing it cuts melanosome transfer by roughly 35 to 68% in cell models. Effects are consistent but modest; it evens tone rather than erasing dark patches.

For post-inflammatory hyperpigmentation, hydroquinone remains a first-line agent in systematic reviews of treatment in skin of color, but outcome data are humbling: across the 2024 JEADV review of PIH treatments, topicals achieved complete clearance in only 5.4% of patients, with partial improvement in about 72%. It lightens marks; it rarely erases them, and marketing that promises full removal overshoots the data.

A 2025 systematic review of clinical trials for solar lentigines reported IPL success rates in the 74 to 90 percent range, with less post-inflammatory hyperpigmentation than cryotherapy. In a hand lentigines study, 62 percent of patients got more than 50 percent improvement. This applies to discrete sun spots in lighter skin; IPL is a poor and often risky choice for melasma, which can worsen with light-based heat.

In a 12-week randomized double-blind trial of 44 patients, retinol 0.5% significantly reduced hyperpigmentation, performing on par with bakuchiol. Beyond small trials like this, dedicated pigment studies of retinol itself are scarce; most retinoid pigment data come from tretinoin.

Salicylic acid peels are marketed for dark spots and post-acne marks, but a 2024 systematic review of post-inflammatory hyperpigmentation treatments (41 studies, 877 patients) found peels overall had the weakest showing: partial response in only 33.3% of peel-treated patients and poor or no response in 66.7%. It may help mild surface pigment as part of broader acne control, but it should not be the primary pigment treatment.

Cosmetic brands increasingly pitch topical TXA for all dark spots and post-acne marks, but the published evidence outside melasma is thin. A 2026 literature review of TXA in melasma and post-inflammatory hyperpigmentation found supportive results but leaned heavily on melasma trials, with PIH data limited to small clinical and observational studies. Reasonable to try given its gentleness; not yet proven for general dark spots.

The same 12-week RCT found bakuchiol significantly reduced hyperpigmentation, equal to retinol 0.5%, with dermatologist grading blinded to treatment. Supporting studies in the 2022 systematic review also reported pigment improvements, but most used bakuchiol blended with other actives, making its solo contribution hard to isolate.

For post-inflammatory hyperpigmentation and general uneven tone, evidence comes mostly from small comparative trials and narrative reviews rather than large RCTs. A 2026 review of peels for pigmentary disorders supports superficial peels as a reasonable option, but in darker skin types the peel itself can trigger new post-inflammatory pigment if depth or aftercare goes wrong, so gains are incremental and technique-dependent.