Ritalinic acid is a substituted phenethylamine and an inactive major metabolite of the psychostimulant drugs methylphenidate, dexmethylphenidate and ethylphenidate.

[1][2] When administered orally, methylphenidate is extensively metabolized in the liver by hydrolysis of the ester group yielding ritalinic acid.

[1] The hydrolysis was found to be catalyzed by carboxylesterase 1 (CES1).

[3] Etymologically, ritalinic acid shares its roots with Ritalin, a common brand name for methylphenidate.

Ritalinic acid is used as an intermediate in the synthesis of methylphenidate and its analogues, such as ethylphenidate and isopropylphenidate.