From keto rash to brittle nails, new research exposes how influencer-backed diets and supplement fads are putting your skin at risk, long before you might notice any other warning signs.
Review: When Diet Trends Go Viral: Cutaneous Manifestations of Social Media-Driven Fad Diets and Supplements. Image Credit: RossHelen / Shutterstock
A recent study published in the journal Cureus reviewed the dermatological consequences of fad diets and supplements.
Digital misinformation and dermatology: A growing concern
The rise of influencer-driven content, aggressive marketing, and online communities has transformed how people access dietary information and select nutritional supplements. While these channels can enhance health literacy, they also facilitate the dissemination of misinformation.
For example, a recent analysis found that only 36% of TikTok nutrition posts were completely accurate, with 55% lacking evidence-based information and 90% failing to discuss both risks and benefits. Recent studies indicate that a substantial proportion of content about nutrition on platforms like TikTok, YouTube, and Instagram may present unverified claims or lack scientific rigor.
The skin often signals early warnings of toxicity and nutritional deficiencies, manifesting changes before systemic symptoms appear. Acute rashes, nail dystrophies, chronic dermatitis, and pigmentary alterations have been reported to be associated with restrictive dietary trends and supplements. The visual impact of skin disease and the popularity of before-and-after imagery amplify the role of digital trends in shaping patient behaviors and expectations.
The Digital-to-Dermis Cascade: How Social Media Drives Diet-Related Skin Disease – The multi-factorial pathways linking fad diets, supplement overuse, and misinformation to dermatologic disease. Social media and online trends drive restrictive or excessive nutrition behaviors, resulting in deficiencies or toxicities that manifest with a range of cutaneous findings. Prevention centers on balanced diet, patient education, and critical appraisal of online health information. Figure rendered by the authors using Procreate (2025).
Bridging clinical practice and the digital world
As such, it is imperative for clinicians to recognize cutaneous manifestations associated with dietary practices and to provide effective counseling and support for digital health literacy among patients. However, robust epidemiological data directly linking social media-driven dietary trends to an increased incidence of dermatologic disease remain limited, and most current evidence is derived from surveys, case reports, and expert opinion rather than large population studies.
The paper emphasizes the importance of a multidisciplinary, patient-centered approach to bridge the gap between digital culture and safe, evidence-based dermatologic care and nutrition. In the present study, researchers synthesized evidence on dermatological consequences of unregulated supplement use and fad diets.
Fad diets and their dermatological effects
The ketogenic diet (KD) has gained considerable popularity, driven by influencers and online communities promising rapid weight loss, neurological benefits, and improved metabolic health. However, KD has distinct dermatologic risks, with keto rash or prurigo pigmentosa being the hallmark complication.
Keto rash typically develops within 1–4 weeks of starting the diet, presenting as intensely pruritic, erythematous plaques and papules on the neck, trunk, and face. Clinical awareness of keto rash is low, often leading to misdiagnosis.
While some evidence suggests that properly supervised ketogenic or hypocaloric diets may benefit conditions like psoriasis or systemic inflammation, these effects are not universal and may be offset by the risk of nutritional deficiencies or adverse events. The mechanism may involve NLRP3 inflammasome suppression, as noted in the paper.
Vegan diets are generally safe, but poorly supplemented or extreme plant-based diets can carry a risk of deficiency in specific nutrients. Iron and vitamin B12 deficiencies are common, resulting in glossitis and hyperpigmentation. Essential fatty acid and protein deficiency could lead to impaired barrier function, xerosis, and brittle nails.
Balanced vegan and plant-based diets, when properly planned, may also reduce the risk or severity of certain skin conditions such as acne, hidradenitis suppurativa, psoriasis, and atopic dermatitis. Besides, vegan diets may occasionally lead to beta-carotenemia. Raw vegan diets are promoted for skin benefits and detoxifying effects.
However, raw vegan diets can be severely low in essential fatty acids, protein, minerals, and vitamins. Beta-carotinemia, essential fatty acid deficiency, and biotin and protein deficiency are well-documented complications of raw veganism. Zero-carbohydrate and carnivore diets are extreme dietary patterns that eliminate plant-based foods and are highly promoted online. With minimal intake of ascorbic acid, even a slight deficiency could lead to delayed wound healing, perifollicular hemorrhage, and scurvy.
The lack of plant polyphenols and dietary fiber decreases short-chain fatty acid production and gut microbial diversity, impairing skin barrier and immunity. The paleolithic diet, which excludes legumes, grains, and dairy, can reduce eczema and acne triggers but carries a risk of deficiency in calcium and other micronutrients.
Further, gluten-free diets show benefit in select autoimmune dermatoses, and the Mediterranean diet lowers the risk and severity of acne, psoriasis, and possibly skin cancer. However, unnecessary restrictions, such as gluten-free diets without a medical indication, can sometimes backfire by inducing nutrient deficiencies.
Supplements: When help turns harmful
The ubiquitous use and excessive intake of dietary supplements have created risks for skin toxicity. Various supplements, such as niacin, selenium, zinc, and proteins, have cutaneous effects, including rashes, hair loss, pigmentary alterations, and nail changes. These manifestations overlap with or mimic other conditions, making diagnosis challenging.
Selenium, niacin, and zinc: Essential but dangerous in excess
While selenium is essential for thyroid function and antioxidant defense, it has a narrow therapeutic window. Selenium overconsumption can lead to selenosis, which has profound systemic and cutaneous consequences. Selenium toxicity may present with hair loss, discolored or dystrophic nails, gastrointestinal upset, fatigue, and garlic breath. Cases of selenosis have occurred from misformulated supplements or excessive consumption of selenium-rich foods, such as paradise nuts. Label inaccuracies and intentional adulteration are well documented, and regulatory oversight for dietary supplements is often inadequate.
Moderate niacin supplementation is beneficial, but excessive consumption may lead to acute and chronic dermatological effects. Niacin flush, i.e., acute niacin toxicity, affects the neck, chest, and face. It is frequently reported after the intake of high-dose supplements or energy drinks. Chronic, high-dose niacin intake may lead to more severe cutaneous consequences, including exfoliative dermatitis and erythroderma.
Zinc is marketed for use in treating acne, hair loss, and supporting the immune system. However, excessive intake disrupts copper absorption, leading to copper deficiency syndrome. Chronic, high-dose zinc intake has become common among athletes and wellness followers.
Copper deficiency syndrome may present with hair and skin hypopigmentation, washed-out hair, persistent ulcers, poor wound healing, anemia, and neuropathy. The biochemical basis is that excessive zinc blocks copper uptake via shared intestinal transporters.
Whey, collagen, and “bodybuilding” supplements
Whey protein is ubiquitous in sports, wellness, and fitness culture and has been linked to an increased risk of acne. It increases insulin and insulin-like growth factor 1 signaling, upregulating androgenic pathways, keratinocyte proliferation, and sebaceous gland activity, all of which contribute to acne pathogenesis. Collagen supplements have also gained popularity for reducing the appearance of aging skin and improving skin elasticity.
However, excess collagen supplementation could result in allergic reactions and gastrointestinal disturbances. Further, energy or bodybuilding supplements contain poorly regulated and risky ingredients that might serve as markers for systemic risk or cause cutaneous toxicity. Supplements may also contain anabolic steroids, prohormones, stimulants, and unlisted drugs.
Performance and bodybuilding supplements may lead to classic cutaneous adverse effects such as severe cystic acne, androgenic alopecia, and striae distensae, and their actual content may not match the label. While omega-3 fatty acid supplements show preliminary evidence of dermatologic benefits at therapeutic doses (2–4 g/day), the evidence for reducing acne remains limited.
Public health and clinical vigilance
Health misinformation remains rampant, with up to half of online advice about supplements being misleading or inaccurate. Some studies have shown that up to 87% of posts about drugs and supplements may contain unsubstantiated or hazardous claims, particularly targeting young adults, athletes, and those pursuing rapid physical transformation.
Misinformation drives behavior, increasing the risk for dermatological sequelae and toxicity. Supplement overuse, poor regulation, and hidden adulterants create risks for hair, nail, and skin diseases. Clinicians should educate patients about the dangers of unproven supplements and extreme diets and advocate for improved digital health literacy and regulation.
Importantly, robust evidence from randomized controlled trials supporting many claims about fad diets and supplements is lacking, highlighting the need for critical appraisal and cautious clinical practice. A careful, patient-centered dietary and supplement history is essential for any individual with new or unexplained cutaneous findings.