What Are the Side Effects of Hair and Skin Supplements in Dermatology? With Rajani Katta, MD

Given the increase in popularity of hair, skin, and nail supplements, Rajani Katta, MD, is urging those in the dermatology field to take a more evidence-based approach to conversations on supplement use before recommending such products to patients.^1,2

Katta, known for her role as an author, a dermatologist, and a clinical faculty member at Baylor College of Medicine and McGovern Medical School at UTHealth, spoke in an interview with HCPLive on-site at the 2026 SDPA Summer Dermatology Conference. She discussed the key messages from her presentation, ‘Supplements in Dermatology: An Evidence-Based Approach,’ highlighting the marketing of various widely available supplements with limited oversight despite their carrying potentially significant safety risks.¹

Throughout her talk and subsequent interview, Katta explained why both clinicians and patients often misunderstand the possible harms to the skin linked with supplement use. She also speaks about a practical framework for dermatologists to assess products before recommending them and touches on why long-term safety deserves an increased level of attention. The following Q&A includes her responses to related HCPLive inquiries:

HCPLive: You gave a talk here at SDPA titled ‘Supplements in dermatology: an evidence-based approach.’ Why did you feel this topic was so important for clinicians working in the dermatology field today?

Katta: When we're talking about skin, hair, and nail supplements, they have exploded. We did a research study where we just looked at the ingredients of skin, hair, and nail supplements available on our local grocery stores. There were so many, and certainly a lot of patients and even providers don't realize all of the risks that are potentially associated with supplements, ranging from an increased risk of cancer to a risk of birth defects. So you really have to be educated on every single supplement ingredient, especially if you're going to recommend that to your patients.

HCPLive: It seems as though the lack of FDA review of supplements is a notable concern. Do you feel that patients who may be anti-supplements should stay away from all of them or simply be more aware of the data on supplements?

Katta: I think it's really important to be aware of the data, but you're absolutely right. That is the main issue, and one of the things I talked about in my talk was the fact that for some pharmaceutical medications, you have to prove efficacy, you have to prove safety, you have to prove quality before a medication can be released. Sometimes patients don't realize that when you're buying a supplement, it seems like it should be safe and that somebody has checked it out. It's not the case, you know. The manufacturer does not have to prove effectiveness or safety. so you really have to educate yourself as a patient and as a provider.

HCPLive: Do you hear from any providers that you know of who are really misguided with regard to supplements? Do you feel that patients are more misguided regarding supplement use and impacts of skin health?

Katta: That's a really good question. I'm not sure, but I will say…there’s an ingredient called saw palmetto, it’s found in some hair loss supplements, and when I've given talks, I've realized that not everybody realizes that that causes birth defects. So if you are recommending this particular supplement, you need to be telling every single woman of childbearing potential that this causes birth defects. I don't know how often that's happening.

HCPLive: What do you feel are some of the other most notable takeaways from your session?

Katta: I have a mnemonic: it's ‘PPIES’; for every single supplement that you are going to recommend or consider recommending P for purity, P for potency, I for interactions, E for efficacy, and S for safety. If nobody has double-checked the supplement for you, you need to do your own analysis of PPIES for every single ingredient in that supplement. That's really one of the main takeaways.

The second takeaway is that, at least for purity and potency, there is a shortcut, which is that you can look for a marker from an independent third-party investigative laboratory that says that they have at least evaluated this particular supplement for purity and potency. That way at least you can feel good about that. So that's an example of something that can help as a shortcut. There are no shortcuts, though, for trying to evaluate efficacy and safety. Unfortunately, that requires some research on your part.

HCPLive: Do you feel that right now, given the increasing awareness of supplements and their potential dangers or upsides or downsides, that we're on a good track? Or do we have a long way to go?

Katta: I think we have a long way to go. I just hear a lot of patients using supplements without questioning if there a potential for risk here. I think they might have questions about if this is going to be effective. But I don't think enough patients say, ‘Could this harm me?’ Unfortunately, there's not a lot of long-term safety data. For example, there was just a study that came out about glucosamine, that's not really used for skin, hair, and nails, it's used for joint symptoms.

But the recent study came out showing that it increased the risk of dementia in patients who had been taking it long term. I worry about this, because we've seen this also with high dose vitamins and minerals, even things like vitamin B6 or beta-carotene, that [there is data suggesting] over the long term they can increase your risk of cancer. I think there aren't enough patients, or providers for that matter, asking these questions about what the long-term safety risk is here.

Disclosures: Katta has reported serving on an advisory board for Vichy Laboratories and is the author of a book on diet and dermatology for the general public.

References

1. Katta R. Integrative Medicine Track: Supplements in dermatology: an evidence-based approach. Session presented at SDPA Summer 2026; June 10–14.

2. Katta R. What Clinicians Should Know About Diet and Skin Disease, With Rajani Katta, MD. HCPLive. July 7, 2026. Accessed July 9, 2026. https://www.hcplive.com/view/what-clinicians-should-know-about-diet-skin-disease-rajani-katta-md.