A new review of scientific studies found that supplements and beauty products are causing more allergic skin reactions than people realize. The research identified common ingredients like vitamin E, turmeric, and ginkgo biloba that can trigger itchy, red skin in some people. The big surprise? Many of these products are labeled as “natural” or “safe,” but they can still cause problems. The study shows that doctors need better tools to identify what’s causing these reactions, and companies need clearer labels so people know exactly what they’re putting on their skin or taking as pills.

The Quick Take

  • What they studied: Are supplements and cosmetic products causing allergic skin reactions, and which ingredients are most likely to blame?
  • Who participated: Researchers reviewed hundreds of published case reports and studies about people who had allergic reactions to supplements and skincare products. No single study group—instead, they looked at patterns across many different cases.
  • Key finding: Certain ingredients commonly found in supplements and beauty products—like vitamin E, turmeric, and ginkgo biloba—are increasingly causing allergic skin reactions. Some people even had serious whole-body reactions, not just local skin irritation.
  • What it means for you: If you develop an unexplained rash after starting a new supplement or skincare product, it might be an allergic reaction. Just because something is labeled “natural” doesn’t mean it’s safe for everyone. Talk to a doctor if you suspect a product is causing your skin problems.

The Research Details

Researchers searched five major medical databases (PubMed, Embase, MEDLINE, Web of Science, and CENTRAL) for all published reports of allergic skin reactions caused by supplements and cosmetic products. They looked at case reports, clinical studies, and other research published over many years to find patterns in which ingredients were causing problems.

This type of study, called a systematic review, is like being a detective. Instead of doing one new experiment, researchers carefully examine all the evidence that already exists to answer a specific question. In this case, they were looking for: What ingredients in supplements and beauty products are making people’s skin react badly? How common are these reactions? What do doctors need to know to help patients?

The researchers organized their findings by ingredient type—vitamins, plant extracts, and antioxidants—and looked at how severe the reactions were and whether doctors could identify the problem through standard allergy testing.

This research approach matters because allergic reactions to supplements and cosmetics are becoming more common, but many doctors don’t recognize them. By reviewing all available evidence, researchers can spot trends that might not be obvious from a single case. This helps doctors know what to look for and helps people understand that natural doesn’t always mean safe.

This is a systematic review, which is considered high-quality research because it looks at many studies rather than just one. However, the review is based on published case reports, which means it only includes reactions that doctors documented and published. Some allergic reactions might not be reported, so the true number could be higher. The review doesn’t have a specific number of participants because it’s analyzing patterns across many different studies and cases.

What the Results Show

The research identified several categories of ingredients that commonly cause allergic skin reactions. Vitamin derivatives—especially vitamin E (tocopherol), vitamin K (phytonadione), and vitamin C (ascorbic acid)—appeared in many cases. These are added to supplements and skincare products because people think they’re healthy, but some people’s immune systems react to them like they’re dangerous invaders.

Herbal extracts were another major culprit. Ginkgo biloba (used for memory), turmeric (used for inflammation), and St. John’s Wort (used for mood) all showed up in allergy cases. Antioxidants like alpha-lipoic acid and resveratrol, which are marketed as anti-aging ingredients, also triggered reactions in some people.

The reactions ranged from mild—just a small itchy rash where the product touched skin—to severe, with some people experiencing whole-body reactions. Doctors confirmed the allergies using patch testing, a method where small amounts of suspected allergens are placed on the skin to see if a reaction develops.

One tricky finding: sometimes patch testing didn’t identify the problem ingredient. This happened when the allergen was a hidden contaminant, an ingredient not listed on the label, or when the ingredient changed chemically after being mixed into the product.

The research found that cross-reactivity is common, meaning if you’re allergic to one ingredient, you might react to similar ingredients too. For example, if you’re allergic to one type of vitamin E, you might react to other forms of it. The researchers also discovered that some ingredients become allergenic only after they oxidize (react with oxygen), which means a product might be safe when new but become problematic as it ages or is exposed to air.

This research confirms what doctors have been noticing more and more: supplements and cosmetics are becoming a bigger source of allergic skin reactions. Previous research focused mainly on traditional allergens like nickel and fragrances, but this review shows that as more people use supplements and ’natural’ skincare, these newer ingredients are catching up as common causes of problems.

The study only looked at cases that were published in medical literature, so it misses unreported reactions. Some people might have allergic reactions but never see a doctor or get properly tested. The review also couldn’t determine exactly how common these reactions are in the general population—it just shows they’re happening more often. Additionally, because supplements and cosmetics aren’t as strictly regulated as medicines, ingredient lists might be incomplete or inaccurate, making it hard to know exactly what caused some reactions.

The Bottom Line

If you develop a rash, itching, or skin irritation after starting a new supplement or skincare product, stop using it and see a dermatologist (skin doctor). They can do patch testing to identify what you’re allergic to. When choosing supplements and cosmetics, check ingredient lists carefully—don’t assume ’natural’ means ‘safe for you.’ If you have sensitive skin or a history of allergies, be extra cautious with new products and introduce them one at a time so you can identify any problems. These recommendations are based on solid evidence from many documented cases.

Anyone who uses supplements or skincare products should be aware of this information, especially people with sensitive skin, existing allergies, or a family history of allergies. If you’ve had unexplained skin reactions in the past, this research might help explain what happened. However, most people can use supplements and cosmetics without problems—this research is about recognizing that reactions can happen and knowing what to do about them.

Allergic reactions to topical products (applied to skin) usually appear within minutes to a few hours of contact. Reactions to supplements taken by mouth might take longer—anywhere from hours to days—as your body processes them. If you stop using the product, mild reactions usually improve within a few days to a week. Severe reactions might need medical treatment.

Want to Apply This Research?

  • Create a log of all supplements and skincare products you use, including the date started, ingredients (if available), and any skin changes you notice. Rate any itching, redness, or irritation on a scale of 1-10 daily. This helps you spot patterns and identify which product might be causing problems.
  • When starting a new supplement or skincare product, introduce only one new item at a time and wait 3-5 days before adding another. This way, if a reaction develops, you’ll know exactly which product caused it. Take a photo of your skin before starting new products so you can compare and notice subtle changes.
  • Set weekly reminders to review your product log and skin condition notes. If you notice any new rashes, itching, or irritation, immediately note which products you’ve used in the past 48 hours. Share this information with your doctor if reactions develop. Over time, you’ll build a personal profile of which ingredients your skin tolerates well.

This research review provides educational information about allergic reactions to supplements and cosmetics but is not medical advice. If you experience skin irritation, rashes, or allergic reactions, consult a dermatologist or healthcare provider for proper diagnosis and treatment. Do not stop taking prescribed supplements or medications without talking to your doctor first. Individual reactions vary greatly, and what causes problems for one person may be safe for another. This information is based on published case reports and may not represent the full scope of reactions in the general population.