Medical-grade formulas carry what percent vitamin C?

A vitamin C label with a percentage on it gives you something to check, which makes it the easiest sign on the bottle to read. MedicineNet gives the range to read it against.

The range

MedicineNet states: "Effective vitamin C products contain between an eight and 20 percent concentration of vitamin C", a figure given for effective products and not tied to the words "medical-grade". The percentage on the label is the thing to compare, not the category name.

Reading the number on a label

Find the concentration printed on the product and hold it next to that range. A product that lists no concentration leaves you nothing to compare. A product that lists one gives you a number you can check against what MedicineNet says effective products contain.

More skin care reading

The Cleveland Clinic newsroom has Dermatologist-Approved Tips for Healthier Skin, and the AAD has a piece on skin care secrets. A routine by decade is laid out by Houston Methodist in its skin care routine for your 30s, 40s, 50s and beyond. Skin is one part of routine care, and the MedlinePlus Medical Encyclopedia covers health screenings for men ages 18 to 39.

Finding the percentage before you buy

Check whether the vitamin C product you own states its concentration, and compare it to the range above. Readers in St. Johns, Florida, who cannot find a percentage on the label can ask the seller for it before buying.