Metamucil Capsules are the convenience pick, and they earn that label honestly — zero mixing, zero grit, zero taste, from the most clinically studied and doctor-recommended psyllium brand. If you travel, work somewhere you can't mix a drink, or simply refuse the grit of powder, they make a daily psyllium habit effortless, and that's a real, underrated advantage because the best fiber is the one you actually take. But the format has an unavoidable cost: each capsule holds only a small amount of psyllium, so a serving is several caps and a cholesterol-range dose is a large handful — which makes capsules the priciest route per gram of actual fiber on this list.
And the water rule still applies in full. We counted the caps, ran the per-gram math, and pressure-tested the convenience case. Here's the full breakdown.