by Bob's Red Mill · Whole-food soluble + insoluble fiber

Whole-food mixed soluble/insoluble fiber plus omega-3s and lignans. Small servings suit a small appetite; must be ground and refrigerated.
Not a supplement in a tub, but worth including: a tablespoon or two of ground flaxseed brings roughly 2-4g of mixed soluble and insoluble fiber plus omega-3s and lignans. The small serving size fits a small appetite, and it stirs into yogurt, oatmeal, or a shake. Must be ground (whole seeds pass through undigested) and kept refrigerated to avoid rancidity. Gentle and food-first, which suits the brand's bias toward eating real food when possible; not as fast or as dose-predictable as a measured fiber powder.
GLP-1 medications slow how fast the gut moves, and you're taking in less of everything, fiber and water included. That combination is why constipation is one of the most common early side effects. The catch: the wrong fiber can make things worse. Highly fermentable types feed gas production in a gut that is already bloated and uncomfortable.
Start at about half the label dose and build up over a week or two, and treat water as non-negotiable, because fiber works by holding water in the stool and taking it dry can backfire. Non-fermenting fibers tend to be the most comfortable starting point. If constipation doesn't ease with fiber, fluids, and magnesium over a couple of weeks, that is worth a call to your prescriber.
Citrucel (methylcellulose)#1 · Non-fermenting bulk-forming fiber
Metamucil / Konsyl (psyllium husk)#2 · Premium gel-forming soluble fiber
Sunfiber (partially hydrolyzed guar gum, PHGG)#3 · Low-gas soluble fiber
FiberCon (calcium polycarbophil)#5 · Non-fermenting bulk-forming caplet
Acacia fiber (gum arabic)#6 · Gentle slow-fermenting soluble fiber
Benefiber (wheat dextrin)#7 · Convenient but fermentable soluble fiberPrices change often; tap through for the current cost. We may earn a commission, which never changes our picks.
This is general information, not medical advice. Talk to your prescriber before adding a supplement, especially if you have kidney disease, heart disease, or take prescription medication.