From the Flinstones to gummies and chocolate, vitamin innovation over the years has taken many forms. Now, there’s a new player in the vitamin space: the vitamin patch.

Vitamin patches, also known as transdermal patches, are widely available online from sources like PatchMD, PatchAid, NutriPatch, and myriad others available on Amazon and holistic wellness-focused sites. They all claim that their vitamin formulas, none of which are regulated or tested by the FDA, are absorbed directly into the bloodstream. Most companies claim that the patches are ideal because they subvert consumption-based issues such as food allergies.

There’s just one problem: There is little evidence that any of these patches work.

Vitamin Formulation Matters

While transdermal patches may be effective for transmitting certain medications, such as nicotine or birth control, there’s little evidence that vitamins are a good candidate for this method, Geeta Yadav, MD, founder and medical director of FACET Dermatology in Toronto, Ontario, told Verywell.

Skin is only permeable to a certain degree. There are seven layers of skin, and most topical products, such as skincare products, only penetrate the stratum corneum (the outermost layer). However, the size and solubility of the particle matters, Yadav said.

“The smaller the molecule of a substance, the more deeply it can penetrate,” Yadav said. “Another factor is whether or not it is lipophilic, meaning it dissolves in fat rather than water. Drugs that dissolve in fat absorb quickly into the bloodstream.”

Other substances, such as the anti-nausea mediation scopolamine, nicotine, fentanyl, or certain chemicals used for birth control, can be small enough and are fat-soluble, allowing them to go deeper and enter the bloodstream through a patch.

Yadav said that vitamins could be administered transdermally, but only if they were formulated as nanoparticles and encased in a lipophilic (fat-soluble) substance. Since vitamins are not regulated by the FDA, there’s little way to know if the vitamins infused in the patches are in these formulations.

“There’s little current evidence that transdermal patches for vitamins can be effective,” Yadav said.

Clinical Research Raises Further Doubts about Vitamin Patches

The concept of transdermal vitamin patches is intriguing, and several small studies have been conducted to investigate whether they might be of help to post-operative bariatric patients. Since these patients have limited stomach capacity, delivering vitamin supplementation transdermally would be very advantageous. However, in one study, patients were tested for serum nutrient levels after using a multivitamin patch for three, six, and 12 months. At the end of the trial, 19% of participants had developed a vitamin D and B6 deficiency. Other patients developed vitamin B1, folate, and zinc deficiencies.

Another study showed similar results, revealing vitamin D deficiencies after one year of patch-delivered multivitamins for bariatric patients. So far, the only glimmer of hope is a small pilot study of 30 healthy adults that showed that vitamin D3 can be successfully administered via a patch and that vitamin D status improved in all of the participants.

After reaching out to PatchAid to ask for clinical evidence that their products worked, Verywell was told that they had no clinical studies available to support their claims. Despite claiming to be “doctor-recommended,” they did not respond with requests for medical contacts that support the product.

Potential for Harm

Although Yadav warns that too much of some vitamins can be toxic, overdosing via vitamin patches doesn’t seem to be a realistic fear, as Sam Tejada, functional medical expert at Liquivida Wellness Center, can attest. He was approached by a vitamin patch company interested in placing their products in his wellness centers. He decided to give the patches a try personally first.

“My own experience was nothing but a nightmare. Based on my micronutrient test, which I did before and after trying the patch, I did not show any change,” Tejada said. “The patch utilizes an adhesive that can be extremely toxic to the skin, and you can potentially absorb those toxins. I had a very bad reaction and had to seek medical treatment from a local dermatologist, ending up with what is called contact dermatitis.”

Tejada attempted to contact the company to investigate his reaction to the adhesive but said he was brushed off.

“There’s a lack of research behind it at this point. I think it’s more of a fad that needs to be evaluated and researched first, and consumers should be aware and stay away,” Tejada said.