How does DoseRank decide what ranks #1?

Each product gets a composite score blending clinical strength, evidence, dose fit, trust and value. The #1 on the DoseRank tab has the highest composite; the other tabs re-rank the same products by Value, Trust, or Popularity. Placement is never paid.

Is a higher dose always better?

No. Dose-fit rewards landing inside the range studied for the outcome — over-dosing (common with melatonin) or under-dosing both lower the score. The goal is the effective dose, not the biggest number.

What does the Value score mean?

The Value score compares a product's price per serving with clinically relevant products ranked for the same outcome. A score of 50 is the typical price; above 50 means better value than typical, while below 50 means the product costs more than typical. It is a 0–100 value signal, not a percentile.

Why is the cheapest product not #1?

Cost is only one input. The cheapest pick here is a citrate form with weaker absorption and a stock-risk flag, so it leads on Value-for-cost but trails on the composite that also weighs evidence, dose fit and availability.

Are these affiliate links?

Retailer links may be affiliate links and DoseRank may earn a commission. Rankings and placement are determined by the scoring model only — never by payment from a brand.

Is this medical advice?

No. DoseRank summarizes evidence to help you choose; it is not a substitute for a clinician, especially if you are pregnant, breastfeeding, on medication, or managing a health condition.

DOSERANKEVIDENCE-BASED SUPPLEMENTS

Reduce IBS symptoms

DOSERANKEVIDENCE-BASED SUPPLEMENTS

Best Supplements for Irritable bowel symptom severity | DOSERANK

Top decision cards

Best products for irritable bowel symptom severity

Ranking by · Composite outcome score

Best overall — the composite outcome score.

Top pick · DoseRank

Why this ranks #1 for irritable bowel symptom severity

Source Naturals, Psyllium Husk Powder, 12 oz (340 g)

Source Naturals$0.18 / serving4.7 · 5,653Available now

Also helps with

Constipation

Satiety

LDL cholesterol

Why this ranks here

Evidence fitPsyllium Husk is the strongest evidence signal for this outcome.
Dose fitPsyllium Husk at 5 g lands inside the studied 5-20 g window.
Price / serving$0.18 per serving — mid price tier for this outcome.
AvailabilityIn stock across major retailers; 99% availability confidence.
TrustStrong trust signals — consistently high marks from verified buyer ratings.

The numbers

5 gIn rangeinside the studied 5-20 g window

Compare top 3 Product data Open at retailer

The rest of the ranking · DoseRank

Top 10 ranked products

Micro Ingredients, Organic Psyllium Husk Powder, 2 lb (907 g)

Micro IngredientsClinical87Dose fit67Popularity88$0.14/ serving

Frontier Co-op, Organic Psyllium Husk, Whole, 16 oz (453 g)

Frontier Co-opClinical87Dose fit67Popularity79$0.20/ serving

Swanson Vitamins, L. Plantarum Probiotic, 10 Billion CFU, 30 Vegan EMBO Caps AP

Swanson VitaminsClinical88Dose fit90Popularity82$0.40/ serving

California Gold Nutrition, LactoBif® 30 Probiotics, 60 Veggie Capsules

California Gold NutritionClinical86Dose fit73Popularity100$0.39/ serving

Vitamatic, Lactobacillus Plantarum, 60 DRcaps® Hypromellose Capsules

VitamaticClinical88Dose fit93Popularity82$0.25/ serving

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Swanson VitaminsClinical86Dose fit67Popularity95$0.21/ serving

Organic India, Organic Psyllium Powder, 6 oz (170 g)

Organic IndiaClinical87Dose fit67Popularity91$0.28/ serving

Frontier Co-op, Organic Psyllium Husk Powder, 16 oz (453 g)

Frontier Co-opClinical87Dose fit70Popularity66$0.34/ serving

California Gold Nutrition, Prebiotic Fiber, 6.3 oz (180 g)

California Gold NutritionClinical87Dose fit71Popularity95$0.70/ serving

Top decision cards

Best products for irritable bowel symptom severity

Ranking by · Composite outcome score

Best overall — the composite outcome score.

Top pick · DoseRank

Why this ranks #1 for irritable bowel symptom severity

Source Naturals, Psyllium Husk Powder, 12 oz (340 g)

Source Naturals$0.18 / serving4.7 · 5,653Available now

Also helps with

Constipation

Satiety

LDL cholesterol

Why this ranks here

Evidence fitPsyllium Husk is the strongest evidence signal for this outcome.
Dose fitPsyllium Husk at 5 g lands inside the studied 5-20 g window.
Price / serving$0.18 per serving — mid price tier for this outcome.
AvailabilityIn stock across major retailers; 99% availability confidence.
TrustStrong trust signals — consistently high marks from verified buyer ratings.

The numbers

5 gIn rangeinside the studied 5-20 g window

Compare top 3 Product data Open at retailer

The rest of the ranking · DoseRank

Top 10 ranked products

Micro Ingredients, Organic Psyllium Husk Powder, 2 lb (907 g)

Micro IngredientsClinical87Dose fit67Popularity88$0.14/ serving

Frontier Co-op, Organic Psyllium Husk, Whole, 16 oz (453 g)

Frontier Co-opClinical87Dose fit67Popularity79$0.20/ serving

Swanson Vitamins, L. Plantarum Probiotic, 10 Billion CFU, 30 Vegan EMBO Caps AP

Swanson VitaminsClinical88Dose fit90Popularity82$0.40/ serving

California Gold Nutrition, LactoBif® 30 Probiotics, 60 Veggie Capsules

California Gold NutritionClinical86Dose fit73Popularity100$0.39/ serving

Vitamatic, Lactobacillus Plantarum, 60 DRcaps® Hypromellose Capsules

VitamaticClinical88Dose fit93Popularity82$0.25/ serving

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Swanson VitaminsClinical86Dose fit67Popularity95$0.21/ serving

Organic India, Organic Psyllium Powder, 6 oz (170 g)

Organic IndiaClinical87Dose fit67Popularity91$0.28/ serving

Frontier Co-op, Organic Psyllium Husk Powder, 16 oz (453 g)

Frontier Co-opClinical87Dose fit70Popularity66$0.34/ serving

California Gold Nutrition, Prebiotic Fiber, 6.3 oz (180 g)

California Gold NutritionClinical87Dose fit71Popularity95$0.70/ serving

Reduce IBS symptoms

Reduce IBS symptoms

Which ingredient types matter for irritable bowel symptom severityOpen to see which ingredient types matter for irritable bowel symptom severity

Fibers & Prebiotics

Probiotics & Microorganisms

Fatty Acids & Lipids

Best products for irritable bowel symptom severity

Source Naturals, Psyllium Husk Powder, 12 oz (340 g)

Micro Ingredients, Organic Psyllium Husk Powder, 2 lb (907 g)

Frontier Co-op, Organic Psyllium Husk, Whole, 16 oz (453 g)

Swanson Vitamins, L. Plantarum Probiotic, 10 Billion CFU, 30 Vegan EMBO Caps AP

California Gold Nutrition, LactoBif® 30 Probiotics, 60 Veggie Capsules

Vitamatic, Lactobacillus Plantarum, 60 DRcaps® Hypromellose Capsules

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Organic India, Organic Psyllium Powder, 6 oz (170 g)

Frontier Co-op, Organic Psyllium Husk Powder, 16 oz (453 g)

California Gold Nutrition, Prebiotic Fiber, 6.3 oz (180 g)

What every metric means

Compare the top 3, side by side

Not sure which is right for you?

Get a personal report

Frequently asked

Which ingredient types matter for irritable bowel symptom severityOpen to see which ingredient types matter for irritable bowel symptom severity

Fibers & Prebiotics

Probiotics & Microorganisms

Fatty Acids & Lipids

Compare the top 3, side by side

Best products for irritable bowel symptom severity

Source Naturals, Psyllium Husk Powder, 12 oz (340 g)

Micro Ingredients, Organic Psyllium Husk Powder, 2 lb (907 g)

Frontier Co-op, Organic Psyllium Husk, Whole, 16 oz (453 g)

Swanson Vitamins, L. Plantarum Probiotic, 10 Billion CFU, 30 Vegan EMBO Caps AP

California Gold Nutrition, LactoBif® 30 Probiotics, 60 Veggie Capsules

Vitamatic, Lactobacillus Plantarum, 60 DRcaps® Hypromellose Capsules

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Organic India, Organic Psyllium Powder, 6 oz (170 g)

Frontier Co-op, Organic Psyllium Husk Powder, 16 oz (453 g)

California Gold Nutrition, Prebiotic Fiber, 6.3 oz (180 g)