On social media today, many influencers are showing off colorful stickers on their arms and bellies, claiming these patches boost their dopamine, improve their moods or give them mental clarity.
Companies selling the adhesives say they work like nicotine or estrogen patches (which are backed by research and approved by the Food and Drug Administration), allowing substances to be absorbed through the skin and into the bloodstream. But can vitamins, herbal extracts and other common wellness patch ingredients also seep into the skin?
“Transdermal drug delivery is a real science,” said Dr. Igor Koturbash, a professor and co-director of the Center for Dietary Supplements Research at the University of Arkansas for Medical Sciences in Little Rock. “But that doesn’t mean any other compound can be successfully delivered through the skin.”
Wellness patches are a growing market. There are dozens marketed for a variety of purposes, such as managing weight, improving focus and boosting energy. Wellness patches, and the supplements they contain, aren’t assessed for safety and effectiveness by the F.D.A. the way medications are. But leaving that aside, are they effective?
How does transdermal drug delivery work?
The main benefit of delivering a drug through a patch is that it offers slow, sustained release, said David Kroll, a professor of natural products pharmacology and toxicology at the University of Colorado Anschutz in Aurora. It also sidesteps the digestive system, which minimizes gastrointestinal side effects.
Taking drugs this way “can be useful for the right compound,” with the right properties and formulation, said Nicole K. Brogden, a professor of pharmaceutics at the University of Iowa who researches transdermal drug delivery.
Patches are also different from topical drugs, like creams, which are generally formulated to have a localized effect and not enter the bloodstream, she added. Several transdermal medications are F.D.A. approved, including nicotine for smoking cessation and others to treat Parkinson’s disease, A.D.H.D. and pain.
When a patch is placed on the body, its active ingredients permeate the outermost layer of skin, which has a “brick-and-mortar type of structure” composed of skin cells and fats, Dr. Brogden said.
Compounds that have a small molecular weight and are fat-soluble are more likely to breach this brick wall, penetrate deeper into the skin’s layers and ultimately reach the bloodstream, she added. Many patches contain permeation enhancers, or substances that help the active ingredients pass, Dr. Kroll said.
Are wellness patch ingredients likely to penetrate the skin?
Few studies have examined wellness patches, so it’s difficult to say which ingredients (if any) will get into the skin, reach the bloodstream and have a therapeutic benefit, Dr. Koturbash said. It would most likely vary by brand and formulation, the amounts contained in the patch (which isn’t always disclosed) and any additional ingredients, such as permeation enhancers, Dr. Kroll added.
One small study compared multivitamin patches against pills in 44 patients for 12 months after bariatric surgery, and those who used patches were more likely to have deficiencies in things like vitamin D, vitamin B12, folate and ferritin.
B12 and other B vitamins, commonly found in dopamine, energy and weight management patches most likely wouldn’t penetrate the skin well because they’re “highly water-soluble,” Dr. Brogden said.
However, a recent study found that microneedles that pierce the skin and then dissolve could help vitamin B12 pass the skin’s outer layer.
Dopamine patches are especially popular, though they don’t contain dopamine itself, but rather precursors of it that brands claim will improve mood or mental focus. This often misrepresents how dopamine functions, and some ingredients may not reach the blood stream.
For example, some dopamine patches have vitamin A, which “really, really likes fat” and may linger in the skin’s lipid layers, Dr. Brogden said. Other ingredients fall into the “maybe” category, she added. L-tyrosine is an amino acid small enough to penetrate the skin, but its specific formulation matters. Even if it is absorbed, Dr. Koturbash said, a few chemical reactions must occur before L-tyrosine can be converted into dopamine.
Plant extracts, like green tea, are even harder to assess as patch ingredients because they contain multiple compounds, Dr. Brogden said.
The plant compound berberine, a common ingredient in weight management patches, can potentially be absorbed through the skin, Dr. Brogden said. And one study with animal skin found that it could be delivered via microneedling. Dr. Koturbash said transdermal berberine is a “promising” alternative to taking the substance orally, which can affect the gut microbiome, but more research is needed.
Should you try a wellness patch?
Many of the supplements used in patches have very little evidence that they live up to companies’ promises. As for the patches themselves, most experts say it’s too early to know whether they can deliver ingredients to the bloodstream.
“It’s an interesting idea,” said Jeremy J. Johnson, a pharmacist-scientist and professor at the University of Illinois Chicago. “I would just like to see more evidence.”
Dr. Koturbash added that the science of wellness patches lags behind the development and availability of products.
There’s also the potential for side effects, such as an allergic reaction, Dr. Johnson said. The patches could interact with certain medications or irritate the skin, said Dr. Koturbash, who suggested talking to your doctor before using them.
“First ask yourself why you’re using the patch,” Dr. Kroll said, when there are proven, science-backed treatments for health issues like fatigue, concentration problems or weight loss.
Patches can also be pricey, costing about $20 to $40 for a month’s supply; you can get a 160-day supply of vitamin B12 supplements for $10. “It’s an extremely expensive way to try and get something you can take orally,” Dr. Kroll said.