Herb & supplement monograph

Sitostanol Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Sitostanol interacts with medications. The heart of this page is the interaction list — every drug Sitostanol is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Sitostanol is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Interaction report

Drugs that interact with Sitostanol

0 medications have a known interaction with Sitostanol, graded by severity. Select any drug for the full evidence-based detail.

We don’t currently list any known drug interactions for Sitostanol. This doesn’t guarantee none exist — always confirm with your pharmacist before combining supplements with your medications.

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Sitostanol combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Monograph

Sitostanol: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Sitostanol is a plant stanol that can modestly lower LDL ("bad") cholesterol by blocking the absorption of cholesterol in the gut. It is best known when combined with related stanols and sterols in fortified foods and is generally considered safe for most adults, but it is not a replacement for prescribed cholesterol medicines. Talk with your pharmacist or doctor before starting it, especially if you take heart or cholesterol drugs.

Part used
Plant sterol/stanol derived from vegetable oils, wood pulp, and other plant sources
Common forms
Fortified margarine and spreads, yogurt drinks, capsules, tablets (often as sitostanol esters)
People commonly use it for
  • High cholesterol
  • Heart health support
  • Lowering LDL cholesterol
  • General cardiovascular wellness

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallUse caution

Generally well tolerated in foods, but high intakes and certain medical conditions warrant caution.

PregnancyInsufficient reliable information

Insufficient reliable information is available; avoid using.

Read the full pregnancy detail
BreastfeedingInsufficient reliable information

Insufficient reliable information is available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Sitostanol is a type of plant stanol, a natural fat-like compound found in plants. It is the saturated (hydrogenated) form of beta-sitosterol, one of the most common plant sterols. Sitostanol is usually made from plant sources such as vegetable oils and wood pulp, and it is often turned into "sitostanol esters" so it mixes well into foods.

You will most often see plant stanols like sitostanol added to fortified foods such as margarine-style spreads, yogurt drinks, and some dietary supplements. These products are marketed mainly to help support healthy cholesterol levels as part of a heart-healthy diet.

How it works

Sitostanol has a chemical shape very similar to cholesterol. In the gut, it is thought to compete with cholesterol for absorption. By taking cholesterol's place, it helps block some dietary and bile cholesterol from being absorbed into the body, so more is passed out in the stool.

With less cholesterol absorbed, the liver can pull more LDL cholesterol from the blood, which may lower LDL levels over time. Unlike its sterol cousins, sitostanol itself is poorly absorbed into the bloodstream, which is one reason it is often viewed as well tolerated.

Most of this understanding comes from human cholesterol studies and laboratory research on how stanols interact with cholesterol in the digestive tract.

Effectiveness

Does Sitostanol work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 4 uses evaluated
1 Possibly effective 3 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.
Possibly Effective Familial hypercholesterolemia
Rating & evidence shown verbatim from Natural Medicines

Taking sitostanol orally in three divided doses daily reduces total cholesterol by 11% to 14% and low-density lipoprotein (LDL) cholesterol by 15% to 33% in children with familial hypercholesterolemia. Sitostanol also seems to improve cholesterol levels in adults with familial hypercholesterolemia who are already being treated with statins. Preliminary clinical research shows that taking sitostanol about 2 grams in three divided doses daily for 6 weeks decreases total cholesterol by 14% and LDL cholesterol by 20% compared to baseline in adults with familial hypercholesterolemia who are already taking simvastatin 20-40 mg daily. Sitostanol does not affect high-density lipoprotein (HDL) cholesterol or triglyceride levels in children or adults with familial hypercholesterolemia.

Sources Ref 3888 Ref 3889 Ref 5438 Ref 90743
Also studied for 3 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Cancer
Rating & evidence shown verbatim from Natural Medicines

A meta-analysis of population research has found that although the highest intake of plant sterols is associated with a reduced risk of cancer when compared with the lowest intake, there is no association between sitostanol and cancer risk based on two available studies.

Sources Ref 106084
Insufficient Reliable Evidence To Rate Esophageal cancer
Rating & evidence shown verbatim from Natural Medicines

In Chinese people with esophageal squamous cell carcinoma, the mortality rate does not seem to differ between those with the lowest versus the highest intake of dietary sitostanol, measured five years before diagnosis.

Sources Ref 112082
Insufficient Reliable Evidence To Rate Obesity
Rating & evidence shown verbatim from Natural Medicines

In Chinese adults, higher dietary intake of sitostanol is inversely related to the risk of being overweight.

Sources Ref 112083

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

Plant stanols like sitostanol are widely added to foods and are generally considered safe for most adults when used as directed. Because stanols are poorly absorbed, they tend to stay mostly in the gut.

People with a rare inherited condition called sitosterolemia (phytosterolemia) should avoid plant stanol and sterol products, since they handle these compounds abnormally. Anyone with a serious medical condition, or who takes cholesterol or heart medicines, should check with a pharmacist or doctor first.

During pregnancy and breastfeeding, there is not enough safety information to recommend supplement-level doses. Food amounts may be acceptable, but it is safest to avoid extra supplements during these times unless your doctor advises otherwise.

Side effects

Sitostanol is usually well tolerated. When side effects happen, they are typically mild and related to digestion, such as gas, bloating, constipation, or loose stools.

Some research has noted that plant stanols and sterols may slightly lower blood levels of fat-soluble nutrients like beta-carotene and certain vitamins. Eating plenty of fruits and vegetables can help. Stop use and seek medical advice if you notice any unusual or allergic reactions.

Sitostanol: Reported Adverse Effects

Documented safety reports on Sitostanol from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Orally, sitostanol is well tolerated. Adverse effects have not been reported in clinical trials in adults or children. However, because sitostanol decreases cholesterol absorption in the gut, it might be expected to produce some gastrointestinal symptoms like diarrhea and excess amounts of fat in the stool (steatorrhea).

  1. Vuorio AF, Gylling H, Turtola H, et al. Stanol ester margarine alone and with simvastatin lowers serum cholesterol in families with familial hypercholesterolemia caused by the FH-north karelia mutation. Arterioscler Thromb Vasc Biol 2000;20:500-6.
  2. Weststrate JA, Meijer GW. Plant sterol-enriched margarines and reduction of plasma total- and LDL-cholesterol concentrations in normocholesterolaemic and mildly hypercholesterolaemic subjects. Eur J Clin Nutr 1998;52:334-43.
  3. Gylling H, Miettinen TA. Cholesterol reduction by different plant stanol mixtures and with variable fat intake. Metabolism 1999;48:575-80.
  4. Gylling H, Puska P, Vartiainen E, et al. Serum sterols during stanol ester feeding in a mildly hypercholesterolemic population. J Lipid Res 1999;40:593-600.
  5. Gylling H, Radhakrishnan R, Miettinen TA. Reduction of serum cholesterol in postmenopausal women with previous myocardial infarction and cholesterol malabsorption induced by dietary sitostanol ester margarine: women and dietary sitostanol. Circulation 199
  6. Gylling H, Miettinen TA. Serum cholesterol and cholesterol and lipoprotein metabolism in hypercholesterolaemic NIDDM patients before and during sitostanol ester-margarine treatment. Diabetologia 1994;37:773-80.
  7. Gylling H, Miettinen TA. Effects of inhibiting cholesterol absorption and synthesis on cholesterol and lipoprotein metabolism in hypercholesterolemic non-insulin-dependent diabetic men. J Lipid Res 1996;37:1776-85.
  8. Gylling H, Puska P, Vartiainen E, et al. Retinol, vitamin D, carotenes and alpha-tocopherol in serum of a moderately hypercholesterolemic population consuming sitostanol ester margarine. Am J Cardiol 1999;145:279-85.
  9. Hallikainen MA, Uusitupa MI. Effects of 2 low-fat stanol ester-containing margarines on serum cholesterol concentrations as part of a low-fat diet in hypercholesterolemic subjects. Am J Clin Nutr 1999;69:403-10.
  10. Heinemann T, Kullak-Ublick GA, Pietruck B, von Bergmann K. Mechanisms of action of plant sterols on inhibition of cholesterol absorption. Comparison of sitosterol and sitostanol. Eur J Clin Pharmacol 1991;40 Suppl 1:S59-63.
  11. Jones PJ, Ntanios FY, Raeini-Sarjaz M, et al. Cholesterol-lowering efficacy of a sitostanol-containing phytosterol mixture with a prudent diet in hyperlipidemic men. Am J Clin Nutr 1999;69:1144-50.
  12. Gylling H, Siimes MA, Miettinen TA. Sitostanol ester margarine in dietary treatment of children with familial hypercholesterolemia. J Lipid Res 1995;36:1807-12.
  13. Miettinen TA, Puska P, Gylling H, et al. Reduction of serum cholesterol with sitostanol-ester margarine in a mildly hypercholesterolemic population. N Engl J Med 1995;333(20):1308-12.
  14. Vanhanen HT, Kajander J, Lehtovirta H. Serum levels, absorption efficiency, faecal elimination and synthesis of cholesterol during increasing doses of dietary sitostanol esters in hypercholesterolaemic subjects. Clin Sci (Colch) 1994;87:61-7.
  15. Plat J, van Onselen EN, van Heugten MM, Mensink RP. Effects on serum lipids, lipoproteins and fat soluble antioxidant concentrations of consumption frequency of margarines and shortenings enriched with plant stanol esters. Eur J Clin Nutr 2000;54:671-7.
  16. Hallikainen MA, Sarkkinen ES, Uusitupa MI. Effects of low-fat stanol ester enriched margarines on concentrations of serum carotenoids in subjects with elevated serum cholesterol concentrations. Eur J Clin Nutr 1999;53:966-9.
  17. Hallikainen MA, Sarkkinen ES, Gylling H, et al. Comparison of the effects of plant sterol ester and plant stanol ester-enriched margarines in lowering serum cholesterol concentrations in hypercholesterolaemic subjects on a low-fat diet. Eur J Clin Nutr
  18. Williams CL, Bollella MC, Strobino BA, et al. Plant stanol ester and bran fiber in childhood: effects on lipids, stool weight and stool frequency in preschool children. J Am Coll Nutr 1999;18:572-81.
  19. Tammi A, Ronnemaa T, Gylling H, et al. Plant stanol ester margarine lowers serum total and low-density lipoprotein cholesterol concentrations of healthy children: the STRIP project. Spec Turku Coronary Risk Factors Intervention Project. J Pediatr 2000;1
  20. Mensink RP, de Jong A, Lütjohann D, Haenen GR, Plat J. Plant stanols dose-dependently decrease LDL-cholesterol concentrations, but not cholesterol-standardized fat-soluble antioxidant concentrations, at intakes up to 9 g/d. Am J Clin Nutr. 2010 Jul;92(1):
  21. Vásquez-Trespalacios EM, Romero-Palacio J. Efficacy of yogurt drink with added plant stanol esters (Benecol®, Colanta) in reducing total and LDL cholesterol in subjects with moderate hypercholesterolemia: a randomized placebo-controlled crossover trial NC
  22. Hallikainen M, Kurl S, Laakso M, Miettinen TA, Gylling H. Plant stanol esters lower LDL cholesterol level in statin-treated subjects with type 1 diabetes by interfering the absorption and synthesis of cholesterol. Atherosclerosis. 2011 Aug;217(2):473-8.
Reports by condition
Diarrhea Gastrointestinal

Although adverse effects have not been reported, sitostanol decreases cholesterol absorption in the gut, and it might be expected to produce some gastrointestinal symptoms like diarrhea and excess amounts of fat in the stool (steatorrhea).

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no official supplement dose set specifically for sitostanol on its own. In studies of plant stanols and sterols, cholesterol-lowering effects are usually seen with daily amounts spread across meals, often delivered through fortified spreads or supplements.

The best approach is to follow the product label and not exceed the recommended amount. Because doses and product strengths vary, ask your pharmacist to help you choose a product and confirm it fits with your overall plan, especially if you already take cholesterol medication.

Pregnancy & Breastfeeding

Sitostanol & Pregnancy

Insufficient reliable information

Insufficient reliable information is available; avoid using.

Sitostanol & Breastfeeding

Insufficient reliable information

Insufficient reliable information is available; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 27 references that drive our Sitostanol 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. Vuorio AF, Gylling H, Turtola H, et al. Stanol ester margarine alone and with simvastatin lowers serum cholesterol in families with familial hypercholesterolemia caused by the FH-north karelia mutation. Arterioscler Thromb Vasc Biol 2000;20:500-6. PubMed
  2. Becker M, Staab D, Von Bergmann K. Treatment of severe familial hypercholesterolemia in childhood with sitosterol and sitostanol. J Pediatr 1993;122:292-6. PubMed
  3. Weststrate JA, Meijer GW. Plant sterol-enriched margarines and reduction of plasma total- and LDL-cholesterol concentrations in normocholesterolaemic and mildly hypercholesterolaemic subjects. Eur J Clin Nutr 1998;52:334-43. PubMed
  4. Gylling H, Miettinen TA. Cholesterol reduction by different plant stanol mixtures and with variable fat intake. Metabolism 1999;48:575-80. PubMed
  5. Gylling H, Puska P, Vartiainen E, et al. Serum sterols during stanol ester feeding in a mildly hypercholesterolemic population. J Lipid Res 1999;40:593-600. DOI
  6. Gylling H, Radhakrishnan R, Miettinen TA. Reduction of serum cholesterol in postmenopausal women with previous myocardial infarction and cholesterol malabsorption induced by dietary sitostanol ester margarine: women and dietary sitostanol. Circulation 199 PubMed
  7. Gylling H, Miettinen TA. Serum cholesterol and cholesterol and lipoprotein metabolism in hypercholesterolaemic NIDDM patients before and during sitostanol ester-margarine treatment. Diabetologia 1994;37:773-80. DOI
  8. Gylling H, Miettinen TA. Effects of inhibiting cholesterol absorption and synthesis on cholesterol and lipoprotein metabolism in hypercholesterolemic non-insulin-dependent diabetic men. J Lipid Res 1996;37:1776-85. DOI
  9. Gylling H, Puska P, Vartiainen E, et al. Retinol, vitamin D, carotenes and alpha-tocopherol in serum of a moderately hypercholesterolemic population consuming sitostanol ester margarine. Am J Cardiol 1999;145:279-85.
  10. Hallikainen MA, Uusitupa MI. Effects of 2 low-fat stanol ester-containing margarines on serum cholesterol concentrations as part of a low-fat diet in hypercholesterolemic subjects. Am J Clin Nutr 1999;69:403-10. PubMed
  11. Heinemann T, Kullak-Ublick GA, Pietruck B, von Bergmann K. Mechanisms of action of plant sterols on inhibition of cholesterol absorption. Comparison of sitosterol and sitostanol. Eur J Clin Pharmacol 1991;40 Suppl 1:S59-63. DOI
  12. Jones PJ, Ntanios FY, Raeini-Sarjaz M, et al. Cholesterol-lowering efficacy of a sitostanol-containing phytosterol mixture with a prudent diet in hyperlipidemic men. Am J Clin Nutr 1999;69:1144-50. PubMed
  13. Gylling H, Siimes MA, Miettinen TA. Sitostanol ester margarine in dietary treatment of children with familial hypercholesterolemia. J Lipid Res 1995;36:1807-12. DOI
  14. Miettinen TA, Puska P, Gylling H, et al. Reduction of serum cholesterol with sitostanol-ester margarine in a mildly hypercholesterolemic population. N Engl J Med 1995;333(20):1308-12. PubMed
  15. Vanhanen HT, Kajander J, Lehtovirta H. Serum levels, absorption efficiency, faecal elimination and synthesis of cholesterol during increasing doses of dietary sitostanol esters in hypercholesterolaemic subjects. Clin Sci (Colch) 1994;87:61-7. PubMed
Keep reading

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.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Brand directory

Brands that make products with Sitostanol

8 brands in our database make a supplement containing Sitostanol.

Product directory

Supplement products with Sitostanol

9 products in our database contain Sitostanol. Open any to see its full ingredient list and every drug interaction we check.

Pharmacist Counseling Corner

Sitostanol: Common Questions

What is Sitostanol used for, and does it work?
People use Sitostanol for many reasons, but the evidence varies by use. According to the Natural Medicines database, there is at least some clinical evidence supporting Sitostanol for Familial hypercholesterolemia. For most other uses it has been studied for, the evidence is currently insufficient to rate. See the graded list on this page, and always confirm with your pharmacist or doctor.
Does Sitostanol interact with prescription medications?
We do not currently list any known drug interactions for Sitostanol. This does not guarantee that none exist, so always confirm with your pharmacist before combining it with your medications.
How are Sitostanol interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Sitostanol with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Sitostanol interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
What is Sitostanol used for?
It is most commonly used to help lower LDL ("bad") cholesterol as part of a heart-healthy diet. Evidence for plant stanols supports a modest cholesterol-lowering effect.
Is Sitostanol the same as beta-sitosterol?
They are closely related. Sitostanol is the saturated (hydrogenated) form of beta-sitosterol; both are plant compounds, but stanols like Sitostanol are absorbed into the body even less than sterols.
Can Sitostanol replace my cholesterol medication?
No. It may modestly support healthy cholesterol levels, but it is not a substitute for prescribed statins or other heart medicines. Never stop a prescribed medication without talking to your doctor.
Is Sitostanol safe during pregnancy?
There is not enough safety data, so supplement-level doses should be avoided during pregnancy and breastfeeding unless your healthcare provider specifically recommends them.

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

Keep exploring

Products that contain Sitostanol

A rotating sample of real supplements in our database that list Sitostanol — open any to see its full ingredients and every drug interaction we check.

See all 9 products with Sitostanol →
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