There are certain grooming habits most men inherit without question, like spraying cologne directly onto the neck. It’s one of the best areas to apply cologne for optimal performance. But lately your algorithm might be making you second-guess that daily ritual. More and more wellness influencers are warning that the chemicals in fragrances head straight to your thyroid and mess with your hormones. Others say that the neck is highly vascular so the chemicals will easily absorb into your bloodstream and “pollute your body.” So is your signature scent actually sabotaging your hormones, or is this just another TikTok spiral worth scrolling past? We spoke to experts to set the record straight.

Is your neck a risky place to spray cologne?

The idea that a pat of cologne on your neck can make a beeline for your thyroid sounds ominous. It’s also scientifically flawed. “The idea that the thyroid is directly absorbing chemicals from products applied to the neck is not anatomically accurate,” says Erum Ilyas, MD, MBE, FAAD, a board-certified dermatologist and the chair of dermatology at Drexel University College of Medicine. “The skin of the neck is separated from the thyroid by multiple layers of tissue, including muscle, and there is no direct pathway from the skin surface to the thyroid gland.” For any ingredient to influence the thyroid, she says it would need to be absorbed through the skin, enter the bloodstream, and then reach the thyroid as a target organ… but there’s no express lane to get there.

That doesn’t mean your neck is the ideal place for a spritz of cologne, either. For starters, the skin on your neck is thinner and more reactive than you think. “While initial contact may not cause a reaction, repeated exposure—like regularly spraying directly onto the neck—can, over time, cause sensitization and eventually allergic contact dermatitis,” says Jody Levine, MD, a board-certified dermatologist and the director of dermatology at Plastic Surgery & Dermatology of NYC. Plus, the neck is routinely exposed to sunlight, which can trigger adverse reactions like hyperpigmentation.

There’s also proximity. Spraying close to your face means you inhale more of it (and its chemical constituents). According to Andrea Gore, PhD, a professor of pharmacology and toxicology at the University of Texas at Austin, nasal exposure can offer a more direct route to the blood-brain barrier via the olfactory system. This could warrant caution when you take a closer look at what your favorite cologne contains.

Safety concerns around fragrance

Zooming out, the concern is less about your neck and more about what’s inside the bottle. Some fragrance formulas include ingredients that have been studied for potential endocrine-disrupting effects. The most scrutinized: phthalates. “Scientific studies consistently show that many phthalates are endocrine-disrupting chemicals (EDCs), meaning that they can interfere with hormones in the body,” Gore says. These hormones—including testosterone, estrogen, and thyroid hormone—affect everything from metabolism and mental health to fertility. Other EDCs to watch out for include parabens and synthetic musks. What makes this tricky is that many colognes and perfumes include one or some of these, even if they’re not listed. (‘Fragrance’ and ‘parfum’ function as umbrella terms on ingredient lists. Specific components—potential EDCs among them—aren’t always disclosed.)

While it’s challenging to source fragrances without these chemicals, some newer brands—including Henry Rose and Dedcool—market themselves as EDC-free.