Drug & supplement interaction

South Beach Diet + Propylthiouracil, PTU

Propylthiouracil, PTU brand name: Propylthiouracil.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between South Beach Diet and Propylthiouracil, PTU 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

South Beach Diet and Propylthiouracil, PTU

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 Propylthiouracil, PTU and South Beach Diet in our sources. This does not guarantee that the combination is completely free of risk — research on South Beach Diet alongside specific medications may be limited.

Worth understanding: our licensed dataset holds no drug-interaction record for South Beach Diet at all — not against Propylthiouracil, PTU, 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.

South Beach Diet is an eating pattern rather than something you take. Ask your pharmacist or doctor before changing how you eat while on a prescribed medicine: some medicines are dosed around meals, and a change in diet can change how they work. 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.

South Beach Diet safety at a glance

South Beach Diet overall Use caution Generally safe for healthy adults, but the strict early phase may not suit everyone.
Pregnancy Use caution Restrictive or low-carb eating is not recommended in pregnancy without medical supervision.
Breastfeeding Use caution Nursing parents need adequate calories and nutrients, so avoid restrictive phases without guidance.

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

Still wondering about combining Propylthiouracil, PTU and South Beach Diet? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests South Beach Diet and Propylthiouracil, PTU May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so following South Beach Diet while taking the medicine can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Vomiting / Nausea reported in 4.3% of FDA reports for Propylthiouracil, PTU Additional detail

    South Beach Diet

    “One case of hyperglycemic ketoacidosis, with symptoms of nausea, vomiting, and abdominal pain, occurred in a non-diabetic 30-year-old patient that had implemented the South Beach diet for 3 weeks.”

    South Beach Diet · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 90101. Chalasani S, Fischer J. South Beach Diet associated ketoacidosis: a case report. J Med Case Rep 2008;2:45. PubMed

    Propylthiouracil, PTU

    Listed in the ADVERSE REACTIONS section of the FDA label for Propylthiouracil, PTU, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for South Beach Diet but not commonly for Propylthiouracil, PTU: stomach pain.

Effects for Propylthiouracil, PTU come from the ADVERSE REACTIONS section of its FDA label; effects for South Beach Diet come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 2,019 voluntary FDA FAERS reports for Propylthiouracil, PTU that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About South Beach Diet or Propylthiouracil, PTU

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers South Beach Diet or Propylthiouracil, PTU, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Propylthiouracil, PTU

This page covers South Beach Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Propylthiouracil, PTU page lists 64 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Ascophyllum Nodosum (moderate).

By severity: 4 major · 51 moderate · 9 minor.

Open the Propylthiouracil, PTU interaction page

How much people look this up

Where South Beach Diet and Propylthiouracil, PTU 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 South Beach Diet
Steady interest

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

29 days ago today
Medication Propylthiouracil, PTU
Top half

#1,184 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 South Beach Diet reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The South Beach Diet and Propylthiouracil, PTU 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 .
Eating pattern

About South Beach Diet

What is South Beach Diet?

  • Weight loss
  • Blood sugar control
  • Reducing cravings for refined carbs
  • Improving cholesterol and heart health
  • General healthy eating

The South Beach Diet is a popular low-glycemic, higher-protein eating plan—not an herb or supplement. It can help some people lose weight and reduce refined-carb cravings, especially in the short term, but long-term success depends on sticking with healthy habits. Talk to your doctor or a dietitian before starting any restrictive diet, particularly if you have diabetes, kidney disease, or take medications.

Structured eating plan with three phases; books, prepackaged meals, and meal-delivery programs

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

South Beach Diet: dosing

There is no "dose" because the South Beach Diet is an eating plan, not a pill or supplement. Instead, you follow the structure of its phases and food lists as described in the official books or program materials.If you choose a prepackaged meal version, follow the program's serving guidance.

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

Read the full South Beach Diet monograph & all interactions
Medication

About Propylthiouracil

What Is Propylthiouracil Used For?

Brand name: Propylthiouracil

Propylthiouracil tablets are used to treat hyperthyroidism — a condition where the thyroid gland produces too much hormone. It is specifically approved for patients with Graves' disease or toxic multinodular goiter who cannot tolerate methimazole and for whom surgery or radioactive iodine therapy is not a suitable option.

Propylthiouracil is also used to reduce hyperthyroid symptoms before a patient undergoes thyroid surgery (thyroidectomy) or radioactive iodine therapy, again in patients who cannot tolerate methimazole. It may also be the preferred antithyroid drug during or just before the first trimester of pregnancy.

See full Propylthiouracil drug information
Keep checking

Other Drugs & South Beach Diet

Browse every other medication we’ve checked against South Beach Diet — 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
2,829 No interaction
No interaction 2,829 drugs checked — show the list

We also checked South Beach Diet against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full South Beach Diet list.

See the full South Beach Diet interactions page
See every supplement checked against Propylthiouracil, PTU, ranked by severity
Evidence & sources

South Beach Diet References

The 1 references that drive our South Beach Diet 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. Chalasani S, Fischer J. South Beach Diet associated ketoacidosis: a case report. J Med Case Rep 2008;2:45. 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

Following South Beach Diet While Taking Propylthiouracil, PTU: Common Questions

Is it safe to follow South Beach Diet while taking Propylthiouracil, PTU?
We do not list a known interaction between South Beach Diet and Propylthiouracil, PTU. 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.
Do South Beach Diet and Propylthiouracil, PTU have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Does Propylthiouracil, PTU interact with any supplements?
Yes. Propylthiouracil, PTU has documented interactions with 64 supplements in our database — South Beach Diet is not one of them. The Propylthiouracil, PTU interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

South Beach Diet monograph Uses, safety profile, and every drug interaction in one place Propylthiouracil drug information The full plain-English guide to this medication Propylthiouracil, PTU supplement interactions Every supplement checked against Propylthiouracil, PTU, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Propylthiouracil, PTU and South Beach Diet?

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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.