CVS sells this as an arthritis cream. The front of the jar lists emu oil, MSM, glucosamine and chondroitin. The FDA panel on the back lists all four as inactive.
The Active Ingredient
Histamine dihydrochloride 0.025%. That’s the only one.
Histamine is a vasodilator. Rubbed into skin it widens surface blood vessels, blood flow increases, the area gets warm, and the warmth competes with the ache. It’s a counter-irritant, the same category as menthol and capsaicin creams, without the cooling or the burn. That’s where the “odor and burn free” claim comes from.
Nothing in the jar reaches the joint. It changes how the skin over the joint feels.
The Inactive List
From the FDA label on DailyMed, NDC 69842-301:
Deionized water, emu oil, butylene glycol, polyacrylamide, sodium polyacrylate, C13-C14 isoparaffin, laureth-7, methylsulfonylmethane, sunflower oil, ethylhexyl stearate, glucosamine HCl, chondroitin sulfate (shark), tocopheryl acetate, trideceth-6, tetrasodium EDTA, potassium sorbate, methylisothiazolinone.
Inactive is a regulatory classification. It means the FDA does not recognise the ingredient as producing the therapeutic effect. So the four ingredients advertised on the carton are, by CVS’s own label, not the medicine. They’re skin conditioners.
Glucosamine Applied to Skin
The oral evidence is weak to begin with. NIH’s review of glucosamine and chondroitin for osteoarthritis found mixed results, with the largest trials showing little to no benefit over placebo.
Then there’s absorption. Glucosamine is a large water-soluble molecule. The stratum corneum blocks large water-soluble molecules. That is what it is for. Topical delivery to a joint capsule is not a realistic expectation regardless of what the oral trials had said.
Check These Two Before Buying
- Methylisothiazolinone. Preservative, common contact allergen. The American Contact Dermatitis Society named it Allergen of the Year in 2013. If wet wipes or shampoos have given you a rash, note it’s in here
- Chondroitin sulfate is shark-derived. Relevant for anyone avoiding animal ingredients. Glucosamine is often shellfish-sourced, so check if you have a shellfish allergy
Uses And Precautions
Label indication: temporary relief of minor aches and pains of muscles and joints associated with arthritis, simple backache, strains and bruises.
Temporary. It treats a symptom for a few hours and does nothing to arthritis itself.
External use only. Not on broken skin. Away from eyes. Don’t bandage the area tightly after applying. Warmth and mild redness are expected, since that is the drug working. Itching, a spreading rash or real irritation are not, and mean stop.
General information, not medical advice. Check with a pharmacist before starting anything new alongside existing medication.