ALPL and premenstrual tension: We found the ratio of PPA/phenylalanine was significantly higher in people with RRMS (adjusted difference=0.38 [95% CI: 0.06–0.71], p = 0.02), as were both HPPA (adjusted difference=0.54 [95% CI: 0.24–0.84], p = 5.53E-04), and HPPA/tyrosine ratio (adjusted difference=0.63 [95% CI: 0.34–0.93], p = 2.81E-05) compared to those with PMS (Fig. 2f).