No, WD-40 is not good for arthritis. It’s an industrial solvent and lubricant made from petroleum-based chemicals that can irritate and damage your skin. Despite a persistent folk remedy suggesting you can spray it on sore joints the way you’d fix a squeaky door hinge, there is no evidence it relieves joint pain, and applying it to your body carries real health risks.
What’s Actually in WD-40
WD-40 is roughly 45 to 50 percent aliphatic hydrocarbon (a petroleum-based solvent), up to 35 percent petroleum base oil, and another 10 to 25 percent of additional hydrocarbons, with carbon dioxide as the propellant. The exact formula is a trade secret, but the safety data sheet makes the general composition clear: this is an industrial chemical mixture designed to displace water, loosen rusted bolts, and protect metal from corrosion. Nothing in it has any known anti-inflammatory or pain-relieving properties.
Why It Can Harm Your Skin
WD-40’s own safety data sheet warns that skin contact “may cause drying of skin and/or irritation” and recommends wearing protective gloves during use. The reason is straightforward. Petroleum solvents are defatting agents, meaning they strip the natural oils from your skin. According to the National Institute for Occupational Safety and Health, repeated or prolonged contact with petroleum distillates results in drying and cracking of the skin.
For someone with arthritis who might apply WD-40 daily over weeks or months, the risks compound. Chronic dermal exposure to hydrocarbons can go beyond skin irritation. The Merck Manual notes that long-term hydrocarbon exposure can cause peripheral nerve damage, affecting strength in the hands and limbs. Liver and kidney function can also be affected with sustained contact. Breathing in the fumes adds another layer of risk: the vapors act as mild narcotics, causing dizziness and drowsiness even at moderate concentrations.
Where the Myth Came From
The idea likely started because the logic sounds intuitive. Joints feel stiff, WD-40 loosens stiff things, so maybe it works on people too. The analogy falls apart immediately when you consider that arthritic joints aren’t rusty metal. Arthritis involves inflammation of the joint lining, breakdown of cartilage, or an immune system attacking your own tissue. A petroleum solvent sprayed on the skin above a joint has no way to reach the cartilage, reduce inflammation, or alter the disease process. Your skin is a barrier, not a gateway for industrial chemicals to lubricate bones.
The WD-40 Company itself does not endorse or suggest any medical use for its product. The safety data sheet explicitly states “do not take internally,” and the recommended response to skin contact is simply to wash it off with soap and water.
Topical Treatments That Actually Work
If you’re looking for something to rub on a painful joint, several over-the-counter options are designed specifically for that purpose and have clinical evidence behind them.
- Topical anti-inflammatory gels. Products like Voltaren Arthritis Pain contain diclofenac, a non-steroidal anti-inflammatory drug that absorbs through the skin and reduces inflammation in the underlying joint. This is the closest thing to what people imagine WD-40 might do, except it actually works and is FDA-approved.
- Capsaicin creams. Brands like Capzasin-HP and Zostrix use capsaicin, the compound that makes chili peppers hot. Applied regularly, it reduces pain signals from the nerve endings in your skin. It’s recommended for both knee and hand osteoarthritis.
- Salicylate rubs. Products like Aspercreme and Bengay contain salicylates, which are related to aspirin and help with mild pain relief when applied topically.
- Menthol and camphor products. Icy Hot and Biofreeze create a cooling or warming sensation that overrides pain signals temporarily. They don’t treat the underlying inflammation, but they can make a sore joint feel better in the short term.
- Lidocaine patches and creams. Products like Salonpas use a topical anesthetic to numb the area, which can help with localized pain.
Each of these was formulated to be applied to human skin repeatedly and safely. They’ve been tested for absorption, irritation, and effectiveness. WD-40 has been tested for none of those things, because it was never meant to go on a person.
The Bottom Line on Home Remedies
Arthritis pain can be persistent and frustrating, which is exactly why folk remedies like WD-40 gain traction. When conventional treatments feel slow or incomplete, the appeal of a simple fix from the garage shelf is understandable. But applying an industrial solvent to your skin doesn’t just fail to help. It introduces chemicals that can dry, crack, and irritate your skin while potentially exposing you to hydrocarbon vapors that affect your nervous system. Proven topical treatments are widely available, affordable, and designed to do what WD-40 cannot.