Self-tanning products offer a popular method to achieve a tanned appearance without the skin damage associated with ultraviolet (UV) radiation. These formulations rely on the primary active ingredient, dihydroxyacetone (DHA), a simple carbohydrate compound. Whether these products can lead to illness is complex, depending largely on the method of application and the route of exposure. This article explores how self-tanners interact with the body and the potential health risks associated with their use.
How Self Tanners Work and Localized Skin Reactions
The tanning effect from DHA results from a chemical process occurring only on the skin’s surface. Dihydroxyacetone reacts with amino acids in the dead skin cells of the stratum corneum, the outermost layer of the epidermis. This non-enzymatic Maillard reaction produces brown pigments called melanoidins, which temporarily stain the skin.
Since DHA is designed to react only with the dead layer of skin, it does not typically penetrate deeper into viable layers or the bloodstream when applied as a lotion or cream. Therefore, most adverse reactions experienced by users are confined to the skin surface. These localized reactions can include irritant or allergic contact dermatitis, leading to symptoms like redness, itching, or a mild burning sensation.
In rare cases, a person may experience an allergic response to DHA or another component, such as fragrances or preservatives. These reactions, which can manifest as hives or a rash, are localized immune responses. The active ingredient can also have a drying effect on the skin, which may cause irritation for individuals with dry or sensitive skin.
Acute Systemic Risks from Inhalation and Accidental Ingestion
While topical application is generally safe, the main concern regarding acute illness comes from internal exposure, particularly through spray or mist application. The U.S. Food and Drug Administration (FDA) has approved DHA only for external use on the skin. The FDA advises against using DHA on mucous membranes, such as the eyes, lips, and inside the nose or mouth, because safety data for these exposure routes has not been submitted or reviewed.
When self-tanner is applied via a spray booth or aerosol, the fine mist creates a risk of inhaling DHA and other ingredients deep into the lungs. Inhaling these airborne particles can lead to immediate, acute symptoms that mimic illness, such as coughing, wheezing, dizziness, or shortness of breath. Individuals with pre-existing respiratory conditions like asthma or chronic obstructive pulmonary disease (COPD) may be particularly vulnerable.
Studies have shown that inhaled DHA can trigger acute inflammatory responses in the lungs of animal models. These findings raise concerns that heavy inhalation or accidental ingestion could lead to systemic effects, as DHA is not approved for internal exposure. To mitigate this risk, consumers should ensure they are in a well-ventilated space and use protective measures like nose filters, lip balm, and eyewear during spray applications.
Potential Long Term Effects of Active Ingredients
Concerns about long-term health effects relate to chronic cellular changes from repeated use. DHA has been shown in laboratory studies to potentially generate free radicals in the skin. This effect, which can be amplified when DHA-treated skin is exposed to UV light, contributes to oxidative stress. Oxidative stress may lead to the acceleration of skin aging or damage to cellular components like DNA.
Although the DHA-induced color offers minimal sun protection, the active ingredient may make the skin more susceptible to sun damage immediately after application. Research indicates that the concentration of DHA found in commercial products can accelerate free radical formation by over 120% when exposed to UV radiation. This suggests that diligent sun protection remains necessary after using self-tanner to reduce potential long-term damage.
Beyond DHA, self-tanning formulas contain various other ingredients, including preservatives like parabens and formaldehyde releasers. Parabens, for example, are sometimes associated with endocrine disruption, though the evidence is mixed and often based on high concentrations. Choosing high-quality products and minimizing internal exposure remains the best strategy for reducing potential chronic health concerns associated with repeated self-tanner use.