Fiber Supplements for Regularity on a GLP-1 Medication

Frequently asked questions

How much fiber a day is recommended for adults?

The adequate intake is about 25g a day for women and 38g for men, or roughly 14g per 1,000 calories eaten. That second figure is the more useful one on a GLP-1 medication, because it scales down as your overall intake does.

What is the difference between psyllium, methylcellulose, and magnesium?

Psyllium and methylcellulose are bulk-forming: they retain fluid in the stool to increase its weight and consistency, and need ample water to work. Magnesium citrate and oxide are osmotic instead, staying in the bowel and drawing water into it. Magnesium excretion depends on kidney function, so reduced renal function is a reason to ask your prescriber first.

Do fiber supplements interfere with my medications?

The evidence here is thinner than the advice circulating online. The best-studied case is levothyroxine, where a systematic review rated the evidence limited and advised separating the two by an hour, and the one crossover study of psyllium found a roughly 9 percent absorption reduction it judged clinically insignificant. There is no reliable general rule, so ask the pharmacist who dispenses your medication.