Psyllium is the most studied fiber supplement for constipation, and the cheapest way to get it is often the plainest. Here is the dose used in studies, how to take it without trouble, and what a gram of fiber actually costs in three very different products.
Psyllium husk comes from the seeds of Plantago ovata. It is mostly soluble fiber. In the gut it absorbs water and swells into a soft gel, which makes stool bulkier and easier to pass. MedlinePlus classifies it as a bulk-forming laxative.
For chronic constipation, the 2023 guideline from the American Gastroenterological Association and the American College of Gastroenterology gives fiber supplements a conditional recommendation: there is evidence of benefit, but it is not strong. Psyllium is the fiber with the most trials behind it.
Constipation studies and clinical guidance typically use about 7–10 g of psyllium a day or more, split into one to three doses. For scale, one level tablespoon of a plain psyllium powder we checked holds 7 g of fiber.
MedlinePlus advises not to take psyllium as a laxative for longer than a week unless your doctor tells you to. If you want to use it every day for chronic constipation, agree on it with your doctor.
We took three products and worked out the price per gram of fiber from each label. Prices are from Vitacost on October 16, 2026, and GutOptim’s official site on October 15, 2026.
| Product | Price and size | Fiber per serving | Price per gram of fiber | Cost of 7 g of fiber a day |
|---|---|---|---|---|
| NOW Foods Psyllium Husk Powder (plain) | $21.31 for 680 g, about 76 servings | 7 g per level tablespoon (9 g) | $0.04 | $0.28 |
| Metamucil 4-in-1, Sugar-Free Orange | $23.10 for 425 g, about 72 servings | 3 g per rounded teaspoon (5.8 g) | $0.11 | $0.75 |
| GutOptim (gut health capsule) | $49–$69 per bottle, 30 servings | 1.5 g blend per 2 capsules; the fiber share isn’t disclosed | at least $1.09 | at least $7.61, about 10 capsules |
What this means: per gram of fiber, Metamucil cost about 2.7 times more than plain psyllium in our check, and the gut capsule at least 27 times more. You pay Metamucil for the flavor and the smooth texture. The capsule’s price buys a blend whose total amount is a fraction of the fiber doses used in studies. Read our GutOptim review for the full label.
Studies typically use about 7–10 g a day or more, split into doses with plenty of water. Start lower, build up over one to two weeks, and follow your product’s label.
Its main ingredient is psyllium husk, with added flavors and, in the sugar-free version, aspartame. In our check it cost about 2.7 times more per gram of fiber than plain psyllium powder.
There is no single best time. What matters is taking it with enough liquid, keeping it at least 2 hours away from medicines, and being consistent.
At first, yes: gas and bloating are common side effects when you start. Starting low and increasing slowly usually helps. If bloating is severe or comes with pain, see a doctor.
If you are comparing ready-made gut capsules, here is what their labels show. Side by side: Gut Save vs DigestiStart vs GutOptim.
Fiber, clay, aloe and one probiotic in a 1.5 g blend
Full ingredient list, but the whole blend is a fraction of the fiber doses used in studies.
Check price on the official site Read the label check
Fish collagen, herbs and probiotics, 500 mg with every dose listed
The most open label of the three, with small amounts of each ingredient.
Check price on the official site Read the label check
11 traditional Chinese herbs in a 500 mg blend
A herbal tonic blend, about 45 mg per herb, with mostly lab and animal studies behind it.
Check price on the official site Read the label check
Honey, bee products, herbs and berberine in a 550 mg blend
Berberine is listed last, so a serving holds about 4 mg of it at most.
Check price on the official site Read the label check