For people with type 2 diabetes, psyllium use (3.1–14 grams per day for 6–12 weeks) may result in reductions in HbA1c levels. However, in the same studies, psyllium’s effects on serum insulin remain unclear.[1][2][3][4]
The gel-forming properties of psyllium (14 grams per day for 6 weeks) appear to reduce the rate of glucose absorption from the intestines, which in turn lowers serum glucose concentrations.[1][5] It should be noted, however, that the response to psyllium seems most pronounced when taken with a meal, and it may vary from person to person, even if improvements are shown on average.[6][7]
Though psyllium husk may reduce the blood glucose concentration acutely, that doesn’t necessarily mean the change persists once the supplementation is stopped.[7] Therefore, it may be best used as a supportive addition to routine care for people with diabetes.[8]