Last updated on March 2020

Effects of Sucralose on Drug Absorption and Metabolism (The SweetMeds Study)

Brief description of study


Artificial sweeteners like sucralose are found in many foods and drinks. Sucralose might affect hormones and cause health changes.


To see if sucralose changes how medicines are absorbed and processed, how hormones are secreted, gut bacteria, and how fat cells are metabolized.


People ages 18-60 who:

  • Are black or Hispanic
  • Weigh more than 110 pounds
  • Have a body mass index of 25-40
  • Do not have a condition that requires drug treatment

Participants will be screened with:

  • Medical history
  • Physical exam
  • Blood, heart, and urine tests

Participants must not eat or drink anything with artificial sweeteners throughout the study.

Over 7 days, Participants will answer questions, and give daily urine samples and 1 stool sample. Participants will repeat these throughout the study.

Overnight Visit 1: participants will fast starting the night before. They will get breakfast at the visit. The visit includes:

  • An IV will be placed in the arm. Participants will get 2 tablets of medicines. Blood will be drawn several times over 24 hours.
  • A piece of fat tissue may be taken from the abdomen (biopsy).
  • Participants will have a sweet drink. Blood samples will be taken over 2 hours.

Then participants will be randomly assigned to take either a sucralose capsule or placebo. They will take it twice a day for 2 weeks. They will complete two 24-hour food diaries.

Overnight Visit 2 repeats Visit 1 except the biopsy.

Then participants will take the capsules for another 2 weeks.

Overnight Visit 3 repeats Visit 1.

Participants may be contacted by phone within 4 weeks after they finish.

Detailed Study Description


Consumption of non-nutritive sweeteners (NNS) has dramatically increased worldwide and is more prevalent in women than men. Similarly, obesity rates have continued to rise, most notably in minorities. Since NNS consumption has been linked to obesity, we propose studying NNS effects specifically in minority women.

NNS are frequently consumed in combination with prescription medications. This necessitates the study of possible NNS-drug interactions. The hypothesis that NNS may affect drug absorption and metabolism is based on a rodent study. In 2008, Abou-Donia et al reported that sucralose increased the activity of P-glycoprotein (P-gp), a membrane transporter involved in absorption and distribution of a wide range of pharmacologic compounds, and CYP3A, a cytochrome P-450 enzyme important to the first-pass metabolism of many drugs.

So far, NNS effects in clinical studies were mostly observed after acute (one time) or short term exposure. For example, we and others found increased incretin and insulin concentrations in response to sucralose alone or in combination with acesulfame-potassium prior to a glucose load. The effects were most pronounced in obese African American women. We also found upregulation of inflammatory cytokines in subcutaneous fat biopsies of obese individuals who reported consumption of NNS compared to non-consumers. Whether these hormonal and tissue responses persist after prolonged exposure needs to be investigated. NNS have also been shown to influence the microbial composition of the oral cavity and the gut. However, most data were generated in mice and do not exist in humans.


Primary Aim: To determine the effects of sucralose (4 mg/kg/day) administered to overweight and obese minority women for 28 days on drug metabolism using digoxin and midazolam as probes for P-glycoprotein and CYP3A, respectively.

Secondary Aims: To investigate the effects of sucralose on

  1. glucose metabolism and incretin secretion
  2. lipid metabolism
  3. intestinal microflora

The study consists of 3 periods. In the first period (run-in, 7 days), participants will be instructed to avoid all NNS (including NNS in cosmetics or health care products). During the second and third periods (14 days each), participants will be randomized to consume either sucralose containing capsules (4 mg/kg/day) or placebo. At the end of each period, the following measurements will be obtained during an overnight hospitalization:

  1. Serial measurements of plasma concentrations of midazolam and digoxin for 24 hours following a single oral dose of each drug
  2. Frequently sampled 2-hour oral glucose tolerance test (OGTT) to measure glucose, insulin, C-peptide, GLP-1, and other gut hormones.

At the end of P1 (run-in, no intervention) and after P3 (sucralose exposure x 4 weeks), subcutaneous fat biopsies will be performed. Stool samples will be obtained throughout.

Clinical Study Identifier: NCT03407079

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