Plecanatide dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Plecanatide is a constipation pill approved in 2017, for long-term constipation with no known cause and for IBS with constipation.
Evidence grade for Plecanatide: Strong. The rule: at least two finished studies in people, and at least 1,000 people who took it. The sum on this page: 2 completed trials, 1,337 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 1,337
- Human studies
- 2
- Found nothing
- 0
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
FDA-approved on 19 January 2017 under NDA 208745, sold as Trulance. It is for adults with long-term constipation that has no known cause, and for adults with irritable bowel syndrome with constipation. It must not be used in children under six, because of the risk of serious dehydration, and it is avoided in children aged six to under 18. Not approved for weight loss, for leaky gut, or for general gut health.
3 effects reported, 3 unwanted, by people using it, not a trial
Goal pages: Gut health
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Plecanatide is a constipation pill, sold as Trulance. It copies a hormone your gut makes, which pulls water into the gut. That softens stool and speeds it along. It is approved for adults only.
What people take it for
- Long-term constipation.
- IBS with constipation.
- Gut health in general, which it was never tested for.
What studies in people showed
In 1337 adults with long-term constipation, 20.1 percent on the 3 mg dose met the bar for lasting relief. On a dummy pill, 12.8 percent did. That is about one extra person in fourteen. The higher dose did no better. In pooled data, diarrhoea hit 5 percent on the drug and 1 percent on the dummy pill. The company ran the main study. Nobody has tested it against linaclotide.
What people report
Reports, not study results
The good
- We have not collected user reports on this one yet.
The bad
- Diarrhoea is the main side effect, usually in the first three days.
- 4 percent quit the studies because of side effects, against 2 percent on the dummy pill.
- It must never be given to children under six.
Where these come from: We have no user reports. The side effects are from the pooled studies and the label on this page.
My bottom line
It works, a little, for real constipation. It is not a gut health tonic. That is a talk with your doctor.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Plecanatide has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Gut and digestion1,337 people · 2 studies
35 of the 36 indexed goals have no study of any kind behind Plecanatide
No study in people, animals or cells on this page reports a result for these. That does not prove Plecanatide does nothing for them. It does mean anything you have heard about Plecanatide and one of these did not come from a study cited here.
Show full evidence
What is Plecanatide?
Plecanatide is a constipation pill approved in 2017, for long-term constipation with no known cause and for IBS with constipation. It is a small protein, 16 building blocks long, that copies one the gut makes itself. In its main study, 20.1 percent of people on 3 mg met the bar for lasting relief, against 12.8 percent on a dummy pill. That is 7.3 more people in every hundred. The claim that it is gentler than linaclotide has never been tested head to head.
Plecanatide is a chain of 16 building blocks. It differs by just one from uroguanylin, a hormone your own gut makes. The FDA approved it on 19 January 2017 for adults with long-term constipation that has no known cause. It was later approved for IBS with constipation. It is a pill, 3 mg once a day. It works almost entirely inside the gut, not in the blood.
The design idea is about acid. Uroguanylin works best in the slightly acidic upper part of the small gut. So the claim is that plecanatide acts in the right place, more like the body's own signal than linaclotide. Linaclotide comes from a bacterial toxin and works the same at any acid level. That is a sensible story. But nobody has tested it against linaclotide head to head. So whether people actually handle it better is still an argument, not a result.
The numbers are worth stating plainly, because results in constipation studies look bigger in a press release than they are. The main study lasted 12 weeks. The bar for lasting relief meant enough full, natural bowel movements in most weeks. 20.1 percent on 3 mg and 20.0 percent on 6 mg met it, against 12.8 percent on a dummy pill. The drug works, and the result is clear. About one extra person in fourteen benefits compared with the dummy pill. The 6 mg dose added nothing, which is why 3 mg is the approved dose.
Diarrhoea is the side effect that limits the dose. In the pooled studies it hit 5 percent on the drug and 1 percent on the dummy pill, usually in the first three days. Like linaclotide, it must not be given to children under six. Young animals given it risked serious drying out.
How does Plecanatide work?
It switches on a receptor called guanylate cyclase-C on the inner lining of the gut. That sets off a signal inside the gut cells. The signal opens a channel that pushes salt into the gut, and water follows. The result is softer stool that moves faster. The same signal may also calm the nerves that carry gut pain. That is the idea behind the belly pain benefit in IBS. Because it comes from uroguanylin, it works best at the slightly acidic level of the upper small gut. That is the claimed difference from linaclotide.
What have studies in people found about Plecanatide?
A finished set of final-stage studies in long-term constipation and in IBS with constipation. The drug clearly beat the dummy pill, by a modest amount. The company ran the studies and wrote most of the papers.
- Main study, 1337 adults: lasting relief in 20.1 percent on 3 mg against 12.8 percent on a dummy pill. That is 7.3 more people in every hundred.
- The 6 mg dose gave 20.0 percent, no better than 3 mg. That is why the approved dose is 3 mg.
- Stool got softer and came more often from week 1, and stayed that way through week 12.
- Pooled safety data, 863 on 3 mg and 870 on a dummy pill: diarrhoea 5 percent against 1 percent, severe diarrhoea 0.6 percent against 0.3 percent. 4 percent quit because of side effects, against 2 percent.
- Nobody has tested it head to head against linaclotide.
What this does not tell you: The lasting-relief bar counts bowel movements over 12 weeks. It does not measure how a person feels overall. A gap of about 7 in every hundred means most people who take it will not meet that bar. The company ran the main study, and its own staff wrote the paper, which the paper says openly. The studies lasted 12 weeks, so nothing here covers years of use. The acid-level claim that sets it apart from linaclotide has never been tested in patients.
The state of the research
Plecanatide is a good example of a lab-bench selling point that never became proof in patients.
Its link to uroguanylin and its sensitivity to acid are real facts about the molecule. The argument that they should give a gentler effect, higher up the gut, than linaclotide makes sense. Marketing has leaned on it for years. What would settle it is a study putting plecanatide against linaclotide, counting diarrhoea and people quitting. That study does not exist. Comparing diarrhoea rates from separate studies is no substitute, because the people, the definitions and the years all differ.
The second thing to flag is the gap between what it is approved for and how drugs like it get talked about in gut health content. This drug was approved to help people with diagnosed long-term constipation go more often. It was not studied for the gut lining, for leaky gut, for gut bacteria, or for general gut health. And it must never be given to young children.
The evidence, in charts
Fig. 1a · how many people
1,337people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| Therapeutic Advances in Gastroenterology 2017 | 1,337 | 100% |
The whole total is one study of 1,337. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 1 more study in people gives no headcount and is not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
2 of 3 sources here are studies in people. The rest is not.
- Study in people · done in people267%
- Review of studies · sums up other studies133%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 3 different years, 2017 to 2023, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Approved
UK
Not approved
AU
Not approved
CA
Not approved
Approved in 1 of 4, by prescription in 0, not approved in 3. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 5 · what the molecule is
- Kind of compound
- Peptide
- Molecule weight
- About 1682 Da. Sixteen amino acids.
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
Half-life as stated on file: Not calculable. The label states that a half-life could not be determined, because systemic absorption is minimal and the drug acts on receptors facing into the gut lumen.
No amino acid sequence is on file for Plecanatide, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2017Randomized clinical trial: efficacy and safety of plecanatide in the treatment of chronic idiopathic constipation
Plecanatide helped chronic constipation, and it helped roughly one extra person in fourteen. 1,337 adults took one of two doses or a dummy pill, and nobody involved knew which. About 20 in every hundred on either dose became lasting responders, against about 13 on the dummy. Both doses worked the same, so the higher one bought nothing. Diarrhoea was more common on the drug. Four of the five authors worked for the company that makes it and held stock, which the paper discloses.
Double-blind placebo-controlled phase 3, 1337 adults meeting modified Rome III criteria randomised to plecanatide 3 mg (n equal to 443), 6 mg (n equal to 449) or placebo (n equal to 445). Durable overall complete spontaneous bowel movement responders: 20.1 percent on 3 mg, 20.0 percent on 6 mg, 12.8 percent on placebo, P equal to 0.004 for each dose. Diarrhoea 3.2 percent, 4.5 percent and 1.3 percent respectively. Four of the five authors were employees and stockholders of the sponsor, Synergy Pharmaceuticals, which the paper discloses.
- Study in people2023Influence of Demographic Factors on Clinical Outcomes in Adults With Chronic Idiopathic Constipation Treated With Plecanatide
The drug works across most kinds of patient, with one gap. Researchers pooled two identical trials, 2,639 adults in all, and split the results by age, weight, race and sex. Both doses beat the dummy pill in nearly every group, including people over 65 and people who were not White. The exception was the higher dose in people aged 65 and over, which did not clearly beat the dummy on how often they went. Diarrhoea was the commonest side effect. This re-analyses old trials rather than running a new one.
A phase 3 randomised analysis examining whether age, sex, race and other demographic factors change the treatment response in chronic idiopathic constipation. This is the genuine randomised evidence in this compound's later literature, and it is an analysis of who responds rather than a new efficacy trial.
- Review of studies2018Plecanatide: a new guanylate cyclase agonist for the treatment of chronic idiopathic constipation
A general review of the drug and where it fits. It is not a study in people and holds no new results. It is useful for the background on why the drug was designed the way it was.
A narrative review of the compound and its place in therapy. Listed here explicitly as a review, because it is sometimes catalogued as human randomised evidence, which it is not. It is useful for context on the uroguanylin rationale and useless as a source of trial results.
Where to buy Plecanatide
Plecanatide is an approved medicine. The approved product comes from a pharmacy, with a prescription. The vials below are sold “for research” and are not the approved drug.
No seller we track lists Plecanatide yet. We read sellers’ public product lists every week, and this section fills in as soon as one does. Every seller, graded
Common questions
Has Plecanatide been tested in people?
Yes. 1,337 people given it across 2 completed trials cited here, 0 of which found nothing. Plecanatide is a constipation pill approved in 2017, for long-term constipation with no known cause and for IBS with constipation.
What is the Plecanatide dosage?
Approved medicine. No human dose established for unlabelled uses. Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose. FDA-approved on 19 January 2017 under NDA 208745, sold as Trulance. It is for adults with long-term constipation that has no known cause, and for adults with irritable bowel syndrome with constipation. It must not be used in children under six, because of the risk of serious dehydration, and it is avoided in children aged six to under 18. Not approved for weight loss, for leaky gut, or for general gut health.
Is Plecanatide FDA-approved?
FDA-approved on 19 January 2017 under NDA 208745, sold as Trulance. It is for adults with long-term constipation that has no known cause, and for adults with irritable bowel syndrome with constipation. It must not be used in children under six, because of the risk of serious dehydration, and it is avoided in children aged six to under 18. Not approved for weight loss, for leaky gut, or for general gut health.
What is plecanatide approved for?
Long-term constipation with no known cause, and IBS with constipation, in adults, at 3 mg once a day. It must not be given to children under six because of a risk of serious drying out. It is also avoided in children aged six to under 18.
Is plecanatide better tolerated than linaclotide?
That is the claim, and it has never been tested. Nobody has put the two head to head. The acid-level argument comes from how the molecule works, not from patients. Comparing diarrhoea rates across separate studies does not answer the question.
How well does it work?
In the main study, 20.1 percent of people on 3 mg met the bar for lasting relief, against 12.8 percent on a dummy pill. That is a clear result, but a modest one. About one extra person gets relief for every fourteen people treated.
Will it help leaky gut or general digestive health?
There is no evidence for that. The studies counted full bowel movements, stool texture and belly symptoms in people with diagnosed constipation. Nobody measured leaky gut in the studies that got it approved.
Does it get absorbed into the bloodstream?
Barely. So little gets into the blood that the label says its half-life could not be worked out. It acts on receptors facing into the gut, which is also why its side effects are almost all in the gut.