Skip to content
rx-laxatives.com

Our Methodology

Every recommendation on rx-laxatives.com is backed by published research. This page explains exactly how we select products, verify claims, score them, keep content current, and make money — so you can judge our process for yourself.

How We Select Products to Review

We cover the major OTC laxatives, stool softeners, fiber supplements, and probiotics sold in the United States. Our selection criteria:

  • Market availability: The product must be available without a prescription at major US retailers (Amazon, Walmart, CVS, Walgreens) or their online equivalents.
  • Published evidence: There must be at least one published clinical study on the active ingredient. We do not review products backed only by manufacturer claims.
  • Reader demand:We monitor search volume data and reader feedback to prioritize the products people are actually comparing. If you want us to review something we haven't covered, let us know.

We do not accept products, samples, or compensation for review from manufacturers. Our evaluations are based on published clinical data, FDA labeling, manufacturer documentation, and aggregated user reports — not on paid placement.

Our Evidence-Based Process

Every product review and buying guide goes through a multi-step verification process before publication. We take this seriously because you're making health decisions based on what we write.

For every product claim, we verify against:

  1. FDA drug labeling and approved indications
  2. Published clinical studies and systematic reviews (PubMed, Cochrane Library)
  3. Manufacturer product documentation and safety data sheets
  4. American Gastroenterological Association (AGA) clinical guidelines
  5. American College of Gastroenterology (ACG) clinical guidelines
  6. Clinical reference databases (Lexicomp, UpToDate)

Every claim — onset time, dosage, side effects, drug interactions — is checked against the sources above. When studies disagree, we note the disagreement and cite both. When evidence is limited, we say so explicitly rather than overstating confidence.

All sources are cited at the bottom of each page with direct links, so you can verify our claims independently. We cite the specific studies and their authors rather than making appeals to unnamed authority.

We do not have a medical professional on staff. Our authority comes from the published peer-reviewed evidence we cite — not from individual credentials. If you need personalized medical advice, please consult your healthcare provider.

How We Evaluate Products

We are a research-based publication, not a testing lab. We do not run a product testing panel and we do not claim first-hand experience we don't have. Here is what we actually do:

  1. Clinical review: We read the published studies for each active ingredient — mechanism of action, efficacy data, side effect profiles, and contraindications.
  2. Label and formulation review: We compare FDA labeling and manufacturer documentation for dosing, active ingredient quantity, onset time, and formulation differences between a brand and its generic equivalent.
  3. Aggregated user reports:We read published user reviews and patient forums at volume, and report the patterns that recur — taste, texture, how a powder mixes, pill size, tolerability. These are things clinical studies don't cover but matter to real users. Where we describe them, we are summarizing what users consistently report, not what we personally experienced.
  4. Price tracking: We check current retail prices across Amazon, Walmart, and major pharmacies. We also verify generic availability and compare price per dose.

How We Score Products

A star rating you cannot check is a star rating you should not trust. So ours is not a number we type in — it is calculated, from one thing above all: how good the evidence is that the active ingredient actually works.

We grade each active ingredient A to D against the clinical literature we cite, then apply a small adjustment for tolerability — how unpleasant or easy-to-misuse the product is in practice. That adjustment is deliberately small. How nice something is to swallow should never outweigh whether it works.

rating = evidence base + tolerability adjustmentwhere an A grade starts at 4.5 stars, B at 3.8, C at 3.0, and D at 2.3.

ProductEvidenceRatingWhy it has that grade
MiraLAXA4.5PEG 3350: grade A evidence, first-line (PMID 35943487); strong AGA-ACG recommendation (PMID 37211380).
MetamucilB4.0Psyllium: the fiber the fiber meta-analysis actually found effective (PMID 35816465); moderate evidence (PMID 35943487).
SenokotA4.0Senna: grade A evidence for short- AND long-term efficacy, first-line (PMID 35943487); conditional AGA-ACG recommendation (PMID 37211380).
Ex-LaxA3.8Sennosides — same active ingredient as Senokot, so the same grade A evidence (PMID 35943487).
DulcolaxB3.5Bisacodyl: moderate (grade B) evidence (PMID 35943487). The AGA-ACG guideline strongly recommends the related stimulant sodium picosulfate (PMID 37211380).
BenefiberC3.3Wheat dextrin: no efficacy evidence for constipation in the sources we cite; it is a fermentable fiber and produces gas (PMID 20482283).
Phillips' Milk of MagnesiaB3.3Magnesium salts: moderate (grade B) evidence; conditional AGA-ACG recommendation for magnesium oxide (PMID 37211380).
CitrucelC3.3Methylcellulose is NOT among the fibers shown effective in the fiber meta-analysis (PMID 35816465), which found psyllium and pectin effective. Chosen for tolerability, not proven efficacy.
Culturelle Digestive DailyC3.0Probiotics for constipation: modest and inconsistent effects (PMID 32005532, 25099542). Not a laxative.
ColaceD2.6Docusate: a randomized, double-blind, placebo-controlled trial found NO benefit over placebo (PMID 22889861). The AGA-ACG guideline does not evaluate it at all. Exceptionally well tolerated — but tolerability is not efficacy.

We changed this, and it changed our rankings

Our ratings used to be hand-typed numbers with no method behind them. When we built this rubric and applied it, the results were uncomfortable. Senna (Senokot, Ex-Lax) is graded A and recommended first-line by the guidelines — and we had it rated below two products with no efficacy evidence at all. Docusate (Colace) was rated the same as senna, despite a placebo-controlled trial finding it no better than placebo. Those ratings have moved, and some of our rankings moved with them. We would rather publish the method and let you check our work than ask you to take a number on faith.

How We Keep Content Current

Medical evidence evolves. Products get reformulated. Prices change. Here's how we keep our content accurate:

  • Quarterly review cycle: Every review and guide is checked at least once per quarter for accuracy — updated studies, reformulated products, price changes, and new competitors.
  • Guideline monitoring: When the AGA, ACG, or other medical societies publish new guidelines relevant to our content, we update affected pages within two weeks.
  • Reader corrections: If a reader reports an error (wrong dosage, outdated price, broken link), we investigate and correct within 48 hours. Email editorial@rx-laxatives.com.
  • Updated dates: Every page shows when it was last updated. We only change this date when a meaningful edit is made — not for minor formatting fixes.

Conflicts of Interest

We earn money through affiliate commissions (see below), which creates a potential conflict of interest. Here's how we manage it:

  • Products are scored before affiliate links are added. The editorial process and the monetization process are separate steps.
  • We earn the same commission rate regardless of which product you buy. Recommending a more expensive product does not earn us more money per click.
  • We frequently recommend generics over brand-name products — including cases where the generic has a lower price and lower commission value.
  • We have never accepted payment from a manufacturer for a review, ranking, or placement.

How We Make Money

Affiliate links: When you buy a product through our links, we may earn a small commission (typically 4-8%). This never costs you extra.

Display advertising: On some informational pages, we show ads. These never appear on product review pages.

Our Independence Promise

No company pays for a higher ranking. Our editorial recommendations are based solely on product merit. We'd rather recommend a $4 generic than a $40 brand-name product if the generic works just as well — and we frequently do.