Disclosed herein is the use of PPAR (Peroxisome Proliferator Activated Receptor) agonists in the manufacture of medicaments for treating lactose intolerance and lactase deficiency. Also disclosed is the treatment of associated symptoms using the PPAR agonists. PPAR agonists useful in the invention include for example (-)-2-R-methoxy-3-(4-aminophenyl)propionic acid and 5-diisopropylaminosalicylic acid.