Salsalate and aspirin produce anti-inflammatory effects after they are converted in the body to salicylic acid. Studies have shown that aspirin can reduce the amount of folic acid in the blood,¹ though it is not known whether this change is significant. Controlled studies are needed to determine whether people taking salsalate are at risk for folic acid deficiency.

Salsalate and aspirin are rapidly converted in the body to salicylic acid. Taking large amounts of aspirin can result in lower than normal blood levels of potassium,² though it is not known whether this change is significant. Controlled studies are needed to determine whether people taking salsalate are at risk for potassium deficiency.

Salsalate and aspirin are rapidly converted in the body to salicylic acid. Controlled studies show that taking aspirin increases the elimination of vitamin C from the body and lowers blood levels.³ Further controlled research is needed to determine whether salsalate specifically reduces vitamin C levels and whether people taking the drug are at risk for vitamin C deficiency.

Willow bark contains salicin, which is related to aspirin. Salsalate, salicin, and aspirin produce anti-inflammatory effects after they have been converted to salicylic acid in the body. Taking aspirin at the same time as other salicylate drugs can result in adverse effects, such as ringing in the ears, dizziness, headache, confusion, and diarrhea.⁴ Though there are no studies specifically investigating an interaction between willow bark and salsalate, people taking salsalate should probably avoid using the herb until more information is available.