Can Skin Tone Affect Your Meds? Study Sheds Light - Video

Skin pigmentation may act as a "sponge" for some medications, potentially influencing the speed with which active drugs reach their intended targets, a pair of scientists report in a perspective article published in the journal Human Genomics.

The researchers argue that a sizable proportion of drugs and other compounds can bind to melanin pigments in the skin, leading to differences in how bioavailable and efficacious these drugs and other compounds are in people with varying skin tones.

“Our review paper concludes that melanin, the pigment responsible for skin color, shows a surprising affinity for certain drug compounds,” said Simon Groen, an assistant professor of evolutionary systems biology at the Institute of Integrative Genome Biology at the University of California, Riverside, and a co-author on the paper. “Melanin’s implications for drug safety and dosing have been largely overlooked, raising alarming questions about the efficacy of standard dosing since people vary a lot in skin tones.”

According to Groen and coauthor Sophie Zaaijer, a consultant and researcher affiliated with UC Riverside who specializes in diversity, equity, and inclusion (DEI) in preclinical R&D and clinical trials, current FDA guidelines for toxicity testing fail to adequately address the impact of skin pigmentation on drug interactions.

In one example, the researchers found evidence of nicotine affinity for skin pigments, potentially affecting smoking habits across people with a variety of skin tones and raising questions about the efficacy of skin-adhered nicotine patches for smoking cessation.

Groen and Zaaijer propose utilizing a new workflow involving human 3D skin models with varying pigmentation levels that could offer pharmaceutical companies an efficient method to assess drug-binding properties across different skin types.

“It's a monumental task, requiring clear lines of communication between academics, industry researchers, clinicians, and regulators,” Zaaijer said. “The future of medicine relies on our capacity to connect these currently isolated operational teams.”

They also encourage patients, their advocacy groups, and clinical trial participants to ask questions related to ancestry-specific drug efficacy and safety, such as, “Has this drug been tested to see if it's safe for people from different ancestral backgrounds, including mine?” Clinicians and pharmaceutical representatives should be able to provide an easy-to-understand document outlining the results of the various tests, the researchers said.

They acknowledge that in the current state of drug development, this will be hard.

“In terms of risk profile testing, drugs are most often tested on one or a few human cell models that mostly come from donors of Northern European descent,” Zaaijer said. “Drugs are then tested in a rodent model. If these tests are successful, drug companies push the drug through to clinical trials. But are drugs ready to be given to a diverse patient group if they haven’t first been tested, for example, on human cell models of different ancestries? Would you bungee jump off a bridge if you knew the ropes had not been tested for your weight category? Unlikely. So why is this currently acceptable with drugs?”

Groen explained that in different ancestral backgrounds, certain genetic variants are more prevalent. Those variants can affect how a drug is metabolized and how it behaves in a body, he said.

Reference: Zaaijer, S., Groen, S.C. Implementing differentially pigmented skin models for predicting drug response variability across human ancestries. Hum Genomics 18, 113 (2024). https://doi.org/10.1186/s40246-024-00677-7