Drug & supplement interaction

Glycomacropeptide + Haloperidol

Haloperidol brand name: Haldol.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Glycomacropeptide and Haloperidol in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

Know someone taking this? Share
Interaction report

Glycomacropeptide and Haloperidol

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Haloperidol and Glycomacropeptide in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Glycomacropeptide at all — not against Haloperidol, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Glycomacropeptide safety at a glance

Glycomacropeptide overall Use caution Generally well tolerated as a food protein, but it is milk-derived and not suitable for those with milk allergy.
Pregnancy Use caution Not enough safety data; use only under medical or dietitian supervision.
Breastfeeding Use caution Not enough safety data; check with your doctor before use.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Haloperidol and Glycomacropeptide? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Glycomacropeptide Itself Has Been Linked To

This is not an interaction — nothing below involves Haloperidol. It is the side-effect record for Glycomacropeptide on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Glycomacropeptide, this list is the first place to look.

  • Bloating or gas / Stomach upset / Diarrhea / Nausea Additional detail

    “Orally, the most common side effects of glycomacropeptide are abdominal discomfort, bloating, burping, and flatulence. Taking skim milk powder enriched with glycomacropeptide and G600 milk fat extract for 3 months has been associated with diarrhea, flatulence, and nausea. However, rates of these effects were similar in the control group.”

    Glycomacropeptide · Natural Medicines adverse-effect record, reported in diarrhea.

    3 sources cited
    1. 113396. Delsoglio M, Capener R, MacDonald A, et al. Evaluation of a New Glycomacropeptide-Based Protein Substitute in Powdered and Liquid Format in Patients with PKU. Nutrients 2023;15(16):3580. PubMed
    2. 96291. Dalbeth N, Ames R, Gamble GD, et al. Effects of skim milk powder enriched with glycomacropeptide and G600 milk fat extract on frequency of gout flares: a proof-of-concept randomised controlled trial. Ann Rheum Dis. 2012;71(6):929-34. PubMed
    3. 96292. Ney DM, Stroup BM, Clayton MK, et al. Glycomacropeptide for nutritional management of phenylketonuria: a randomized, controlled, crossover trial. Am J Clin Nutr. 2016;104(2):334-45. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Glycomacropeptide — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Haloperidol’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Haloperidol column appears here.

Everything else you take

See Every Supplement That Interacts With Haloperidol

This page covers Glycomacropeptide only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Haloperidol page lists 211 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 11 major · 157 moderate · 43 minor.

From our pharmacist’s overview on the Haloperidol page

“Haloperidol (Haldol) is a potent antipsychotic prescribed for schizophrenia and severe agitation, and the 211 supplements on this list warrant genuine care, starting with the 11 rated major. Most of the trouble runs through the liver enzymes that clear haloperidol from the body.”

Reviewed by 2 · Jul 18, 2026

Open the Haloperidol interaction page

How much people look this up

Where Glycomacropeptide and Haloperidol Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Glycomacropeptide
Steady interest

#1,243 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Haloperidol
Top half

#960 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Glycomacropeptide reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Glycomacropeptide and Haloperidol records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Glycomacropeptide

What is Glycomacropeptide?

  • Phenylketonuria (PKU) nutrition
  • Protein source low in phenylalanine
  • Gut and digestive health
  • Prebiotic support
  • Appetite and satiety

Glycomacropeptide (GMP) is a milk-derived protein fragment best known as a low-phenylalanine protein source used in medical foods for people with phenylketonuria (PKU). It is also being studied for gut health and appetite, but evidence for most non-PKU uses is still limited. Talk to your doctor or dietitian before using GMP products, especially if you have a metabolic condition.

Peptide derived from milk casein (whey-based) · Medical foods, protein powders, capsules, ready-to-drink formulas

An interaction check asks whether these two react with each other — it does not ask whether Glycomacropeptide is a good idea for someone in your situation. Here is what our Glycomacropeptide record says about it on its own.

Glycomacropeptide: dosing

There is no single standardized dose of glycomacropeptide for general use. The right amount depends on why it is being used. For PKU, the amount is carefully calculated by a metabolic dietitian based on a person's protein needs and phenylalanine limits.For protein powders and other supplements, follow the directions on the product label. Avoid taking more than the label suggests.

From our Glycomacropeptide monograph — the full record covers uses, side effects and every documented interaction.

Read the full Glycomacropeptide monograph & all interactions
Medication

About Haloperidol

What Is Haloperidol Used For?

Brand name: Haldol

Haloperidol treats schizophrenia and other psychotic disorders. Uses depend on the product.

Haloperidol tablets and oral solution are also used to control tics and vocal utterances of Tourette’s Disorder in children and adults. They are used for severe behavior problems and hyperactivity in children, but only after psychotherapy or non-antipsychotic medicines have failed. One haloperidol injection product (Haloperidol, intramuscular) is also labeled for Tourette’s Disorder. Haloperidol decanoate injections (including Haldol Decanoate) are for schizophrenia only.

See full Haloperidol drug information
Keep checking

Other Drugs & Glycomacropeptide

Browse every other medication we’ve checked against Glycomacropeptide — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Glycomacropeptide References

The 12 references that drive our Glycomacropeptide monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. van Calcar SC, MacLeod EL, Gleason ST, et al. Improved nutritional management of phenylketonuria by using a diet containing glycomacropeptide compared with amino acids. Am J Clin Nutr 2009;89(4):1068-1077. PubMed
  2. Keogh, J. B. and Clifton, P. The effect of meal replacements high in glycomacropeptide on weight loss and markers of cardiovascular disease risk. Am J Clin Nutr 2008;87(6):1602-1605. DOI
  3. Dalbeth N, Ames R, Gamble GD, et al. Effects of skim milk powder enriched with glycomacropeptide and G600 milk fat extract on frequency of gout flares: a proof-of-concept randomised controlled trial. Ann Rheum Dis. 2012;71(6):929-34. PubMed
  4. Ney DM, Stroup BM, Clayton MK, et al. Glycomacropeptide for nutritional management of phenylketonuria: a randomized, controlled, crossover trial. Am J Clin Nutr. 2016;104(2):334-45. PubMed
  5. Daly A, Evans S, Chahal S, et al. Glycomacropeptide: long-term use and impact on blood phenylalanine, growth and nutritional status in children with PKU. Orphanet J Rare Dis 2019;14(1):44. doi: 10.1186/s13023-019-1011-y. PubMed
  6. Tiele A, Daly A, Hattersley J, et al. Investigation of paediatric PKU breath malodour, comparing glycomacropeptide with phenylalanine free L-amino acid supplements. J Breath Res 2019;14(1):016001. doi: 10.1088/1752-7163/ab4097. PubMed
  7. Larsen ER, Juel A, Jensen E, Hollyer TR, Wegener G. Dietary supplementation with casein glycomacropeptide, leucine and tryptophan reduces plasma amino acid levels in men. Acta Neuropsychiatr 2022;34(2):69-76. PubMed
  8. Delsoglio M, Capener R, MacDonald A, et al. Evaluation of a New 'Mix-In' Style Glycomacropeptide-Based Protein Substitute for Food and Drinks in Patients with Phenylketonuria and Tyrosinemia. Nutrients 2023;15(16):3598. PubMed
  9. Delsoglio M, Capener R, MacDonald A, et al. Evaluation of a New Glycomacropeptide-Based Protein Substitute in Powdered and Liquid Format in Patients with PKU. Nutrients 2023;15(16):3580. PubMed
  10. Daly A, Högler W, Crabtree N, et al. A Three-Year Longitudinal Study Comparing Bone Mass, Density, and Geometry Measured by DXA, pQCT, and Bone Turnover Markers in Children with PKU Taking L-Amino Acid or Glycomacropeptide Protein Substitutes. Nutrients 2 PubMed
  11. Pena MJ, Pinto A, de Almeida MF, et al. Continuous use of glycomacropeptide in the nutritional management of patients with phenylketonuria: a clinical perspective. Orphanet J Rare Dis 2021;16(1):84. PubMed
  12. Daly A, Högler W, Crabtree N, et al. Growth and Body Composition in PKU Children-A Three-Year Prospective Study Comparing the Effects of L-Amino Acid to Glycomacropeptide Protein Substitutes. Nutrients 2021;13(4):1323. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Glycomacropeptide and Haloperidol Together: Common Questions

Is it safe to take Glycomacropeptide with Haloperidol?
We do not list a known interaction between Glycomacropeptide and Haloperidol. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Does Haloperidol interact with any supplements?
Yes. Haloperidol has documented interactions with 211 supplements in our database — Glycomacropeptide is not one of them. The Haloperidol interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Haloperidol and Glycomacropeptide?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.