Is sincalide FDA-approved, and what does the research show?

What is sincalide?

Sincalide is a small peptide, a short chain of amino acids, the units that proteins are built from ¹. The label of one product, Sincalide for Injection, describes it as "a synthetically-prepared C-terminal octapeptide of cholecystokinin" ¹. In plain words, it is a manufactured copy of the last eight amino acids of cholecystokinin, a hormone often shortened to CCK ⁴, ¹. The body makes cholecystokinin itself, and the label compares the release of bile after sincalide with the body's response to its own hormone ¹.

Sincalide is not a wellness, weight-loss or performance peptide. That label calls it "a cholecystokinin (CCK) analog," an analog being a compound built to act like a natural one ¹. Doctors give it into a vein during a diagnostic test, to make the gallbladder squeeze, the pancreas secrete or the small bowel move its contents along ¹. Two FDA applications cover it: Bracco's for Kinevac, which Fresenius Kabi also labels as Sincalide, and MAIA Pharmaceuticals' NDA 210850, distributed by Fosun Pharma USA ², ³.

Is sincalide FDA-approved?

Yes, as a prescription diagnostic agent. FDA approved Kinevac (sincalide for injection) on July 21, 1976, under NDA 017697 ². An NDA is a new drug application, the file a company submits to FDA for approval. The second product, Sincalide for Injection, was approved on November 22, 2022, under NDA 210850, held by MAIA Pharmaceuticals, and Drugs@FDA lists it simply as Sincalide ¹, ³. The record classes that approval as "Type 5 - New Formulation or New Manufacturer" ³.

Drugs@FDA lists both products with the marketing status "Prescription" as of November 9, 2026, the date of the record's data ², ³. Drugs@FDA's data of November 9, 2026, lists two sincalide applications, NDA 017697 and NDA 210850 ², ³. Kinevac's own label is marked "Rx only" ⁴.

The label of Sincalide for Injection says sincalide "is indicated in adults to" do three things ¹. The first is to "stimulate gallbladder contraction, as may be assessed by various methods of diagnostic imaging, or to obtain by duodenal aspiration a sample of concentrated bile for analysis of cholesterol, bile salts, phospholipids, and crystals" ¹. The gallbladder is the small sac that stores bile, a digestive fluid. Duodenal aspiration means drawing fluid through a tube from the duodenum, the stretch of small intestine just past the stomach.

The second use is to "stimulate pancreatic secretion in combination with secretin prior to obtaining a duodenal aspirate for analysis of enzyme activity, composition, and cytology" ¹. Cytology is the study of cells under a microscope, and the partner the label names there is another hormone. The third use is to "accelerate the transit of a barium meal through the small bowel, thereby decreasing the time and extent of radiation associated with fluoroscopy and x-ray examination of the intestinal tract" ¹. A barium meal is a drink that shows up on X-rays, and fluoroscopy is a moving X-ray picture.

Each of the three uses is a step in a diagnostic test, so the approval covers no treatment of any condition ¹. Kinevac's label carries the same three indications ⁴.

See the FDA status of every peptide, updated weekly.

How does sincalide work?

The mechanism comes from the FDA-approved label of Sincalide for Injection ¹. "When injected intravenously," it says, sincalide "stimulates gallbladder contraction and reduction in size" ¹. The label adds: "The evacuation of bile that results is similar to that which occurs physiologically in response to endogenous cholecystokinin" ¹. Endogenous means made by the body.

Sincalide "also stimulates pancreatic secretion and intestinal motility causing pyloric contraction and slows gastric emptying" ¹. Motility is the muscular movement of the gut, the pylorus is the valve at the stomach's exit, and gastric emptying is the passage of food out of the stomach. Given with the partner hormone that the second indication names, sincalide raises "both the volume of pancreatic secretion and the output of bicarbonate and enzymes" ¹. Doctors then assess the pancreas by measuring and analyzing the fluid drawn from the duodenum ¹.

The effect on the gallbladder is quick. After a rapid injection into a vein, "maximal contraction of the gallbladder occurred in 5 to 15 minutes" ¹. The label counts a reduction of at least 40 percent in the gallbladder's size on X-ray as "generally considered satisfactory contraction" ¹.

What does the research show?

The evidence is an FDA approval that dates from 1976 ². The current labels carry no clinical studies section, and they give no count of patients studied for any of the three uses ⁴, ¹.

Studied in people: a multicenter study, published online January 15, 2010 and in the February 2010 issue, gave sincalide to 60 healthy volunteers at four U.S. medical centers ⁵. It used cholescintigraphy, a nuclear medicine scan in which a radioactive tracer injected into a vein fills the gallbladder ⁵. The measure was the gallbladder ejection fraction, the share of its contents the gallbladder empties after sincalide ⁵. The volunteers were 32 women and 28 men aged 20 to 62, screened to have no digestive disease ⁵.

Each volunteer had three scans on separate days, in random order, with the same total dose infused over 15, 30 or 60 minutes ⁵. There was no placebo, a dummy treatment for comparison, and no patient group: the comparison was among the three infusion lengths ⁵. The 60-minute infusion gave the most consistent results ⁵. Its coefficient of variation, a measure of how widely results scatter from person to person, was 19 percent ⁵. The 95 percent confidence interval, the range the true figure probably lies in, was 16 to 23 ⁵.

The coefficient was 35 percent (29.2 to 42.1) for the 30-minute infusion and 52 percent (44 to 63) for the 15-minute infusion ⁵. The differences were unlikely to be chance (P < 0.0007) ⁵. From the 60-minute scans the authors set a lower limit of normal, an ejection fraction of 38 percent ⁵. That was the first percentile of the healthy group's results, the level below which about 1 in 100 healthy results would be expected to fall ⁵. They wrote that this infusion method "should become the standard for routine clinical use" ⁵.

Bracco Diagnostics, the company Kinevac is made for, funded the study through an unrestricted grant to a Society of Nuclear Medicine council and supplied the drugs ⁵, ⁴. The paper states that the company "had no involvement in the development of the protocol or its analysis" ⁵.

The study did not test whether the scan helps patients ⁵. Its authors noted that at least 22 published investigations found a low ejection fraction predicted relief of symptoms after gallbladder removal in patients without gallstones ⁵. About 6 others did not ⁵. Two literature reviews, they added, "found insufficient evidence to confirm the diagnostic utility" of the scan for predicting that outcome ⁵. The reviews called for a well-designed prospective study, one that follows patients forward from the test ⁵.

Research history, studied in people: in the early 1980s two experiments measured food eaten during an infusion of "the C-terminal octapeptide of cholecystokinin" ⁶, ⁷; the 1982 abstract calls it intravenous ⁷. One was in 12 lean men and one in 8 obese men, and each compared the octapeptide with an infusion of saline (salt water) ⁶, ⁷. The label of Sincalide for Injection describes sincalide in the same words, but neither abstract says the octapeptide infused was a commercial sincalide product ¹, ⁶, ⁷.

In the first, published in February 1981, the 12 lean men ate an average of 122 grams less food during the octapeptide infusion than during saline ⁶. In the second, published in October 1982, six of eight obese men ate significantly less during the octapeptide infusion than during saline ⁷. "Significantly" is the statistical term for a difference unlikely to be chance. The second was double-blind, meaning the men and the staff were not told which infusion was running ⁷.

The 1981 authors wrote that the results "offer promise for the possible use of the octapeptide as an appetite suppressant" ⁶. The 1982 authors wrote that the "therapeutic potential of CCK-8 for the treatment of obesity deserves investigation," CCK-8 being their short name for the octapeptide ⁷. No approved use for appetite or weight followed, and every indication on the two sincalide labels is diagnostic ⁴, ¹. Each abstract reports food eaten during the two infusions, and neither reports body weight ⁶, ⁷.

What are the side effects?

On the label of Sincalide for Injection, the most frequent adverse reactions, at "20% or greater," are abdominal discomfort or pain and nausea ¹. It adds that these "may not necessarily indicate an abnormality of the biliary tract unless there is other clinical or radiologic evidence of disease" ¹. The biliary tract is the gallbladder and the ducts that carry bile. The reactions come from clinical trials and from reports sent in after marketing, "from a population of uncertain size" ¹. For that reason, the label says, their frequency cannot always be estimated reliably ¹.

Other reactions on the label include seizures, headache, vomiting, flushing, high blood pressure, diarrhea and an urge to defecate ¹. It also lists vasovagal reactions, a reflex drop in heart rate and blood pressure, with dizziness, fainting and loss of consciousness, "generally self-limiting" ¹. In the study of 60 healthy volunteers, 2 reported mild nausea and abdominal cramping, both during the 15-minute infusion ⁵.

The label contraindicates sincalide, meaning it must not be given, in patients with "a history of a hypersensitivity reaction to sulfites or sincalide" and in patients with "intestinal obstruction" ¹. A hypersensitivity reaction is an allergic-type reaction, and an intestinal obstruction is a blocked bowel. The product contains sodium metabisulfite, "a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people" ¹. Anaphylaxis is a sudden, severe allergic reaction.

Since marketing began, "anaphylaxis, anaphylactic shock and other serious hypersensitivity reactions have been reported during and within one hour following administration" ¹. The label says "appropriate medical support should be readily available" when sincalide is given ¹.

A second warning concerns gallstones ¹. In patients with small stones, the contraction "could lead to the evacuation of the stones from the gallbladder, resulting in their lodging in the cystic duct or in the common bile duct" ¹. Those ducts drain the gallbladder and carry bile to the intestine. A quick injection "may cause adverse reactions such as nausea, vomiting, abdominal pain or cramping, dizziness, and flushing," which the label calls "generally transient" ¹. For two of the three uses, it offers a slower infusion as the way to reduce those injection reactions ¹.

"Based on limited human data and mechanism of action," the label warns that sincalide "may cause preterm labor or spontaneous abortion," that is, early labor or miscarriage ¹. It has no data on sincalide in breast milk ¹. For children, the label says safety and effectiveness "have not been established" ¹. The label says clinical studies of sincalide, which it does not describe, did not include enough people aged 65 and over to show whether they respond differently ¹.

Drugs that speed or slow the gallbladder's movement "may interfere with the response to sincalide" ¹. In an overdose, the label expects gut symptoms and low blood pressure with dizziness or fainting, effects it says "should be of short duration" ¹. Long-term animal studies of cancer risk, genetic damage and fertility "have not been performed," the label says ¹.

In sport

WADA, the World Anti-Doping Agency, does not name sincalide on its 2026 Prohibited List ⁸. Section S2 of the list covers peptide hormones, growth factors, related substances and mimetics, meaning substances that imitate them ⁸. Neither sincalide nor cholecystokinin appears in it or in any other section ⁸. One method rule bears on the route, because the label allows sincalide to be given by infusion ¹. Rule M2.2 prohibits "Intravenous infusions and/or injections of more than a total of 100 mL per 12-hour period except for those legitimately received in the course of hospital treatments, surgical procedures or clinical diagnostic investigations" ⁸.

Section S0 of the list reads: "Any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use ... is prohibited at all times" ⁸. FDA's approval is for diagnostic use: the label says "Sincalide for Injection is indicated in adults to: stimulate gallbladder contraction ...," and it names two other diagnostic uses ¹.

What JumpstartMD offers

JumpstartMD does not prescribe sincalide. Our peptide library covers it so you have the facts on its FDA status and the evidence, current as of November 10, 2026.

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Compounded medications are not FDA-approved, and FDA does not review their safety, effectiveness, or quality before they are marketed. A licensed clinician decides after an evaluation whether a peptide is appropriate for you, and not every patient will qualify.