5-Methylpyrazole-3-carboxylic acid forms salts with basically substituted adenine bases of type (4) or (5), which have significantly more lipolysis inhibitory activity than the free acid itself. The substance tested, 6-amino-9-[2-hydroxy-3-(N-methyl-N-2-hydroxyethyl)-aminopropyl]-purine-5-methyl pyrazole-3-carboxylate (16), causes a significant reduction of serum FFA levels in fasted rats, even at the very low dosage of 0.150 mg/kg b.w., whereas the free 5-methylpyrazole-3-carboxylic-acid shows significant activity in this model only at doses of 2 mg/kg b.w. and above. The salt also shows similar activity on serum triglycerides. The effect on FFA, triglyceride and cholesterol levels, respectively, in fasted rats lasts for at least 8 h.