What Is Vicks Made Of? Active and Inactive Ingredients

Vicks VapoRub contains three active ingredients: camphor, menthol, and eucalyptol (also called 1,8-cineole), suspended in a thick petrolatum base along with several inactive botanical oils. These three compounds are responsible for the familiar cooling sensation and cough-suppressing effect, though the way they work is more interesting than most people realize. The inactive ingredients do more than just hold the ointment together, and the safety profile of the product deserves more attention than it typically gets, especially around young children.

The Three Active Ingredients

Vicks VapoRub is marketed as a topical antitussive and analgesic for use with minor upper respiratory tract infections or muscle and joint aches.¹ The three active ingredients, each present in relatively small concentrations, are:

Camphor (about 4.8%): A waxy, white substance derived from the wood of the camphor laurel tree or synthesized industrially. It provides the warming-then-cooling sensation and acts as a mild pain reliever and cough suppressant.
Menthol (about 2.6%): An organic compound extracted from mint oils or made synthetically. It produces the strong cooling feeling in your nose and throat and is the primary driver of that “I can breathe again” sensation.
Eucalyptol (about 1.2%): The main chemical component of eucalyptus oil. It contributes to the sharp, clean smell and has properties that help with airway congestion and inflammation.

These percentages come from the standard U.S. product label. The rest of the jar is inactive ingredients.

The Inactive Ingredients and What They Do

The inactive ingredient list on a Vicks VapoRub label reads like a small herbalist’s cabinet. The base is petrolatum, which is the thick, greasy petroleum jelly that gives VapoRub its ointment texture. Petrolatum serves as the carrier: it keeps the active ingredients from evaporating too quickly, lets the rub spread smoothly on skin, and creates an occlusive layer that slowly releases vapors as your body heat warms it.

Beyond petrolatum, the inactive ingredients include cedar leaf oil, nutmeg oil, turpentine oil, and thymol.² Each of these has its own aromatic and biological properties. Turpentine oil has a long folk-medicine history as a chest rub ingredient. Thymol, derived from thyme, has mild antiseptic qualities. Cedar leaf oil and nutmeg oil contribute to the distinctive smell that most people associate with being sick as a child. None of these are listed as active ingredients on the label, which means the manufacturer is not making therapeutic claims about them individually, but they do contribute to the overall sensory experience and may have mild biological effects of their own.

How Menthol Creates the Feeling of Clear Airways

Menthol is probably the most interesting ingredient in the jar from a scientific standpoint, because what it does and what it feels like it does are two different things. When you inhale menthol vapors, you feel like your nasal passages have opened up. Your breathing feels easier, cooler, and less obstructed. But when researchers actually measure airway resistance before and after menthol inhalation, they consistently find no measurable change. In a randomized controlled crossover study, upper airway resistance was virtually identical during menthol inhalation compared to a sham treatment.³

So what is actually happening? Menthol triggers a cold-sensitive ion channel called TRPM8 on sensory nerve endings in your nasal passages. These are the same nerve endings that fire when cold air hits your nose. When menthol activates them, your brain interprets the signal as coolness and openness, even though the physical dimensions of your airways have not changed. Research confirms that our perception of nasal patency depends on mucosal cooling rather than on actual nasal resistance or airway width.⁴

This is not a flaw or a scam. The subjective feeling of congestion is one of the most miserable parts of a cold, and if menthol makes you feel less stuffed up, you sleep better and feel better, even if airflow measurements have not budged. Clinical trials on aromatic ointments containing menthol, eucalyptus, and camphor found that patients experienced faster perceived decongestion and significant improvements in reported sleep quality.⁵ For most adults, that relief of symptoms is the whole point.

How Camphor and Eucalyptol Contribute

Camphor works through a different set of receptors than menthol. It activates and then strongly desensitizes TRPV1, the receptor best known for responding to capsaicin (the heat compound in chili peppers). This is what gives camphor its initial warming sensation followed by a numbing or analgesic effect. Research has shown that camphor desensitizes TRPV1 more rapidly and completely than capsaicin does, and it also blocks TRPA1, another pain-related receptor. This desensitization may underlie camphor’s pain-relieving properties.⁶ That is why VapoRub is also marketed for muscle aches, not just coughs.

Eucalyptol (1,8-cineole) is the workhorse of eucalyptus oil and has been studied in clinical trials for respiratory conditions including chronic obstructive pulmonary disease, asthma, bronchitis, and rhinosinusitis. It has anti-inflammatory, antimicrobial, and bronchodilatory properties.⁷ Eucalyptus essential oils more broadly can help relieve congestion and ease symptoms of coughs, colds, and sinusitis.⁸ Of the three active ingredients, eucalyptol probably has the strongest evidence for actual physiological effects on the airways, rather than just altering your perception of them.

The Cough-Suppressing Effect

Vicks VapoRub’s label claims it is a cough suppressant, and this is mainly attributed to menthol and camphor. Menthol’s cough-suppressing effect appears to work through the same TRPM8 channels in nasal sensory neurons discussed above. The cooling sensation inhibits respiratory reflexes and irritation, reducing the urge to cough. Research suggests that the activation of TRPM8 in nasal sensory neurons plays a larger role in this antitussive effect than receptors located deeper in the lungs.⁹ Animal studies have confirmed that menthol suppresses cough via nasal TRPM8-expressing nerve fibers, with the effect being most pronounced when the compound reaches the nasal mucosa directly.¹⁰

This is worth knowing because it means the typical application method matters. Rubbing VapoRub on your chest so the vapors rise toward your nose is more aligned with how the cough suppression works than, say, applying it to the soles of your feet (a popular folk remedy with no evidence behind it). The active ingredients need to reach the cold-sensitive nerve endings in your nasal passages to do their job.

Safety Concerns Worth Knowing About

VapoRub is broadly safe for adults when used as directed on the label, but there are a few risks that catch people off guard.

The biggest concern is camphor toxicity in young children. Camphor is genuinely dangerous if swallowed, and the amounts in a jar of VapoRub are large enough to matter. In children under six, exposure to as little as 500 mg of camphor has been cited as a cause of death, and 750 to 1,000 mg can cause seizures. Products containing 10% camphor (which is higher than VapoRub’s roughly 4.8%, but exists in other over-the-counter products) pack 500 mg into just one teaspoon.¹¹ VapoRub’s lower concentration reduces the risk per volume, but a toddler who eats a generous scoop of VapoRub can still ingest a harmful dose. The product label states it should not be used on children under two, and most pediatricians extend caution to children under six. Keep the jar out of reach.

A less dramatic but still real concern is skin irritation. VapoRub contains several botanicals that can cause allergic contact dermatitis in sensitized individuals. Turpentine oil, eucalyptus oil, and cedar leaf oil are the usual culprits, though case reports exist of VapoRub itself directly causing allergic reactions.² If you develop redness, itching, or a rash where you applied it, stop using it.

A third risk involves the petrolatum base and a habit some people develop of applying VapoRub inside their nostrils to relieve congestion. Chronic intranasal application of petroleum jelly has been linked to exogenous lipoid pneumonia, a condition where inhaled oil droplets accumulate in the lungs and cause inflammation.¹² Case reports continue to document this condition in patients with long-term habits of applying petroleum-based products inside their noses.¹³ VapoRub’s label explicitly says not to put it in or near the nostrils, and this is one of those label warnings that has real clinical backing.

Vicks VapoRub Versus Other Vicks Products

People often say “Vicks” as a shorthand for VapoRub, but the Vicks brand spans a range of products with very different ingredient lists. Understanding the differences matters because they are not interchangeable.

The Vicks Inhaler, a small plastic stick you sniff, is a completely different product. Its active ingredient is levmetamfetamine (a decongestant that is pharmacologically distinct from its infamous molecular cousin). Its listed inactive ingredients include bornyl acetate, camphor, lavender oil, menthol, and methyl salicylate.¹⁴ The overlap with VapoRub is camphor and menthol, but the core mechanism is different: the inhaler delivers an actual vasoconstrictor to shrink swollen nasal tissue, while VapoRub relies on aromatic vapors and sensory nerve tricks.

Vicks BabyRub, designed for infants three months and older, deliberately excludes camphor and menthol, which are considered too strong for very young children. It substitutes fragrances like rosemary, lavender, and aloe in a petrolatum base. It has no drug claims and is marketed as a soothing rub rather than a medicine. Vicks VapoSteam, a liquid added to steam vaporizers, contains camphor as its active ingredient and delivers it through heated water vapor rather than skin contact. Each product in the line targets a slightly different use case with a different formulation.

Off-Label and Folk Uses

VapoRub has accumulated an outsized folk reputation over the decades. People apply it to everything from toenail fungus to insect bites to headaches. Some of these uses have at least a thread of plausibility; others are pure tradition.

The toenail fungus application is the most studied off-label use. A systematic review of complementary therapies for onychomycosis identified two studies that specifically examined VapoRub as a treatment.¹⁵ The evidence is thin but not zero. Thymol and eucalyptol both have documented antifungal properties in laboratory settings, and the petrolatum base creates an occlusive environment over the nail. Whether this translates to reliable clinical improvement is another question, and the existing studies are small. If you have a mild case and months of patience, it is low-risk to try, but it should not replace prescription antifungals for moderate or severe infections.

The “VapoRub on the feet” remedy for coughs, typically done at bedtime with socks over the application, is one of the more persistent folk claims. There is no published evidence supporting it, and the proposed mechanism (that nerve endings in the feet somehow communicate with the cough center) does not hold up anatomically. The menthol vapor has to reach your nasal passages to activate the TRPM8 receptors that suppress cough. With VapoRub sealed under socks at the far end of your body, very little vapor reaches your nose. If people feel it works, the likely explanation is either placebo or that enough vapor still wafts upward under the covers to have a mild effect, in which case applying it to the chest would be more efficient.

Why the Petrolatum Base Matters More Than You Think

Petrolatum is not just an inert carrier. It plays a functional role in how VapoRub delivers its active ingredients. Your body heat gradually warms the ointment after application, which raises the vapor pressure of camphor, menthol, and eucalyptol and causes them to evaporate slowly into the air around your nose and mouth. A thinner base, like a water-based gel, would release the volatiles too quickly, giving you an intense burst followed by nothing. The thick petrolatum slows the release, which is why a single application can last several hours overnight.

Petrolatum also creates a moisture barrier on the skin that can soothe irritated, chapped areas around the nose from repeated blowing. For people with colds, the skin between the nose and upper lip often becomes raw, and the occlusive layer provides some protection. Just keep it on the outside. As noted in the safety section, applying petroleum-based products inside the nostrils is a different situation entirely.

Skin Sensitization and Fragrance Allergy

The botanical oils in VapoRub’s inactive ingredient list are worth flagging for anyone with known fragrance sensitivities. Turpentine oil is a well-documented contact allergen. Cedar leaf oil and nutmeg oil contain compounds that can trigger reactions in sensitized individuals. Even eucalyptus oil, which is part of the active ingredient eucalyptol’s parent plant, can cause dermatitis in some people. The overall rate of allergic reaction to VapoRub is low in the general population, but if you already know you react to fragrance mixes on standard patch testing, approach VapoRub with caution. A small test application on the inner forearm, left for a few hours, is a reasonable way to check before smearing it across your chest.

Children’s skin is more permeable and more reactive than adult skin, which is another reason the product carries age restrictions. The combination of camphor’s toxicity risk and the higher absorption rate through thinner pediatric skin makes standard VapoRub unsuitable for very young children. Vicks BabyRub exists specifically to address this, stripping out the ingredients most likely to cause problems.

How Storage and Temperature Affect the Product

Because the active ingredients are volatile compounds dissolved in a semi-solid petrolatum base, storage conditions affect how well VapoRub works. Heat accelerates evaporation. A jar left in a hot car or near a radiator will lose potency over time as the camphor, menthol, and eucalyptol gas off into the air inside the container. The product does not spoil in a food-safety sense, since petrolatum is extremely stable and the active ingredients have antimicrobial properties, but a jar that no longer smells strong when you open it has likely lost a meaningful fraction of its volatile compounds. Room temperature storage with the lid tightly closed is the way to preserve it. Most people keep VapoRub for years, and a well-sealed jar stored at normal indoor temperatures retains its potency far longer than one that gets opened frequently or left unsealed.