Vicks VapoRub contains three active ingredients: synthetic camphor (4.8%), menthol (2.6%), and eucalyptus oil (1.2%). The rest of the ointment is a blend of petrolatum and several lesser-known essential oils that contribute to its distinctive smell and therapeutic effect. Here’s what each ingredient does and why it’s in the formula.
The Three Active Ingredients
Camphor is the largest active component at 4.8% of the formula. It works by interacting with temperature-sensitive ion channels in your airways, reducing the chemical signals that trigger your cough reflex. When you’re fighting a cold, the virus makes those nerve channels more reactive, and camphor helps raise the threshold it takes to set off a cough. It also creates a mild warming sensation on the skin, which is part of the soothing feeling people associate with the product.
Menthol makes up 2.6% of the formula and is responsible for the cooling sensation. It activates cold-detecting receptors (called TRPM8 channels) in your nasal passages through the trigeminal nerve, creating the feeling that your nose is more open and you’re breathing more freely. This effect is largely subjective. Studies have found that menthol improves the sensation of nasal breathing without actually increasing measurable airflow. Still, that perception of relief is real and meaningful when you’re congested.
Eucalyptus oil rounds out the active ingredients at 1.2%. It works on some of the same nerve pathways as camphor, suppressing the cough response through a slightly different mechanism. Eucalyptus oil has a long history as an inhalant for respiratory symptoms, and its sharp, clean scent is a major part of what makes VapoRub smell the way it does.
The Inactive Ingredients
The base of VapoRub is petrolatum, the same petroleum jelly found in products like Vaseline. It serves as the carrier for all the active and aromatic oils, giving the product its thick, greasy ointment texture and helping it cling to skin so the vapors release slowly over time.
Mixed into that base are several essential oils that most people don’t realize are there: cedarleaf oil, nutmeg oil, turpentine oil, and thymol (a compound derived from thyme). These aren’t just for fragrance. Each has a specific pharmacological reason for being included.
Cedarleaf oil and nutmeg oil both act as inhaled expectorants, meaning they help loosen mucus in your airways when you breathe in their vapors. Research by E.M. Boyd in the 1960s and 70s found that while many oral expectorants had surprisingly little real effect, certain inhaled oils, including cedarleaf, worked even at levels too low to consciously smell. Nutmeg oil’s expectorant properties come largely from its high camphene content, a compound chemically related to camphor.
Thymol acts as a counterirritant, meaning it creates a mild irritation on the skin’s surface that distracts from deeper discomfort like chest tightness or muscle aches. It also has anti-inflammatory properties tied to its effect on the early stages of the body’s inflammatory response. Turpentine oil serves a similar counterirritant role and adds to the product’s penetrating vapor.
How the Formula Works Together
VapoRub is designed to be applied to the chest, throat, or back, where body heat slowly releases the active vapors. You inhale them as you breathe, and they interact with nerve receptors in your nose, throat, and upper airways. The combined effect targets your cough reflex through multiple pathways at once: camphor and eucalyptus oil suppress cough signaling directly, menthol creates the sensation of clearer breathing, and the secondary oils help loosen mucus.
None of these ingredients cure a cold or kill viruses. What they do is reduce the severity of symptoms, especially nighttime coughing and the subjective feeling of congestion, enough to help you sleep. That’s the primary use case most people reach for VapoRub to address.
Camphor and Age Restrictions
Camphor is the ingredient that carries the most safety concern. At 4.8%, VapoRub’s camphor concentration falls within the range the FDA permits for over-the-counter topical products (up to 11% for external analgesics). But camphor is toxic if swallowed, and in young children, it can irritate the airways rather than soothe them, potentially increasing mucus production and making congestion worse.
The American Academy of Pediatrics recommends VapoRub only for children age 2 and older. For babies and toddlers, Vicks makes a separate product called Vicks BabyRub, which is approved for infants 3 months and older. BabyRub uses fragrances and aloe vera in a petroleum jelly base but contains no camphor, menthol, or eucalyptus oil. It’s essentially a scented moisturizer rather than a medicated product.
What About Other Vicks Products?
It’s worth noting that VapoRub is just one product in the Vicks line, and the ingredients vary significantly across them. Vicks inhalers, liquid medications, and throat drops each have their own formulations. When people ask “what is Vicks made of,” they’re almost always asking about the classic ointment in the blue jar. That formula, a petrolatum base with camphor, menthol, eucalyptus oil, and a handful of traditional essential oils, has remained largely unchanged for over a century.