Supplement Fillers to Avoid: A Pharmacist’s Guide to Excipients

Introduction

When you buy a supplement, the vitamins, minerals or botanical extracts are only part of what is inside the capsule. The rest may include excipients: ingredients added to help powders flow through machinery, fill a capsule, hold a tablet together, prevent clumping or improve stability.

That does not make every excipient dangerous. Many serve a legitimate manufacturing purpose and are used in very small amounts. However, not every excipient is necessary, some may be unsuitable for particular people, and others are included mainly to make large-scale manufacturing faster or easier.

The useful question is not simply, “Are fillers bad?” It is:

• What is this ingredient doing in the product?
• Is it necessary?
• Could the supplement have been made without it?
• Is there a reason you personally may want to avoid it?

This guide examines the fillers, binders, flow agents, coatings, colours and sweeteners commonly found in supplements. We will look at ingredients including magnesium stearate, maltodextrin, talc, silicon dioxide, titanium dioxide and microcrystalline cellulose—and separate genuine concerns from claims that are not supported by good evidence.

What Are Excipients in Supplements?

Excipients are the ingredients included alongside a supplement’s active vitamins, minerals, amino acids or botanical extracts.

They are not normally added for their nutritional benefit. Instead, they help the product move through manufacturing equipment, remain stable, hold its shape or become easier to swallow.

You may find them listed on a label as “other ingredients”, rather than under the nutritional information.

The term inactive ingredient is also commonly used, although it can be misleading. Excipients may not be nutritionally active, but they can still affect the size, texture, stability and dissolution of a tablet or capsule.

Why Are Fillers and Excipients Used?

There are several practical reasons a manufacturer may add an excipient.

To create a consistent dose

Some nutrients are required in tiny amounts. A capsule containing 150 micrograms of iodine, for example, cannot be filled with iodine alone.

A suitable carrier or filler can help distribute a small quantity of an active ingredient evenly throughout the formulation, so that each capsule provides a consistent dose.

To help powders flow

Powdered minerals, vitamins and botanical extracts do not always move cleanly through manufacturing equipment. They may clump, absorb moisture or stick to machinery.

Flow agents and lubricants can make the production process faster and more consistent. Magnesium stearate and silicon dioxide are commonly used for this purpose.

To hold a tablet together

Tablets need to remain intact during manufacturing, packaging and transport. Binders help the ingredients hold their shape, while disintegrants are added to help the tablet break apart after it has been swallowed.

Capsules often require fewer of these ingredients because the powder is held inside a separate capsule shell.

To improve stability and shelf life

Some excipients help protect ingredients from moisture, oxygen, light or microbial contamination. These may include anti-caking agents, antioxidants, stabilisers or preservatives.

Their purpose is to help the supplement remain consistent throughout its stated shelf life.

To change the taste or appearance

Colours, flavourings, coatings and sweeteners are often used in gummies, chewable tablets, liquids and powders.

These ingredients may make a supplement easier or more pleasant to take, but they do not usually improve its nutritional value.

Are Excipients Always Necessary?

No—but their presence does not automatically indicate a poor-quality supplement either.

Some excipients perform a clear and useful technical function. Others are chosen because they make manufacturing quicker, reduce waste, lower production costs or create a more visually appealing product.

The amount required also depends on the formulation. A high-dose capsule may have very little empty space, while a tablet containing several low-dose nutrients may need additional ingredients to manufacture it reliably.

A long ingredient list should not automatically cause alarm. The better questions are:

• What function does each ingredient perform?

• Is it present for the consumer or mainly for the manufacturing process?

• Has the manufacturer explained why it is used?

• Could the same product be made with fewer unnecessary ingredients?

The Main Types of Excipients Found in Supplements

The word filler is often used for every non-active ingredient in a supplement. In reality, excipients perform several different jobs.

Understanding the difference matters. A capsule shell, for example, serves a very different purpose from a lubricant added to make manufacturing equipment run more efficiently.

One ingredient can perform more than one function. Cellulose derivatives, for example, may be used as a filler, binder, coating or capsule shell depending on their precise form.

This is why an unfamiliar ingredient should not be judged by its name alone. Its purpose, quantity, source and the type of supplement all matter.

For the remainder of this guide, we will concentrate on the excipients consumers search for most frequently: magnesium stearate, maltodextrin, talc, titanium dioxide, silicon dioxide, microcrystalline cellulose, artificial colours and sweeteners.

Magnesium Stearate

Magnesium stearate is one of the most commonly discussed excipients in supplements. Despite its name, it is not included as a meaningful source of magnesium.

It is a magnesium salt of fatty acids and is normally used as a lubricant. A small amount can prevent powdered ingredients from sticking to machinery and help tablets or capsules move through production more efficiently.

Why is magnesium stearate controversial?

Magnesium stearate is hydrophobic, meaning it repels water. Laboratory and formulation studies have shown that its concentration and the time for which it is mixed with other ingredients can affect how quickly certain tablets dissolve.

However, evidence that the small quantities normally used in supplements meaningfully reduce nutrient absorption in humans is limited. Claims that magnesium stearate damages the immune system or creates a harmful “biofilm” are also not supported by good human evidence.

Magnesium stearate is an approved food additive in the UK, listed as E470b, and available safety assessments have not identified a genotoxic concern at typical dietary exposures.

Should you avoid magnesium stearate?

There is no strong evidence that everybody needs to avoid it.

However, magnesium stearate provides no nutritional benefit. It is included to make manufacturing easier, and some consumers prefer products formulated without it when an alternative manufacturing process is available.

At Arbor Vitamins, we do not use magnesium stearate in our formulations. This is a formulation choice—not a claim that the ingredient is inherently toxic. We prefer to keep non-active ingredients to the minimum required to manufacture a consistent, stable product.

Read our detailed guide to supplements without magnesium stearate.

Maltodextrin in Supplements: Is It Bad for You?

Maltodextrin is a highly processed carbohydrate made by partially breaking down starch—usually from maize, rice, potato or wheat—into a fine, water-soluble powder.

In supplements, it may be used to:

• Add bulk to a small dose of an active ingredient

• Carry flavours, colours or botanical extracts

• Improve the consistency of powders

• Prevent ingredients clumping during manufacturing

• Make powdered products dissolve more easily

Should You Avoid Maltodextrin?

Maltodextrin is not inherently toxic, and the tiny amount present in a capsule is unlikely to have a meaningful effect on most people.

However, it is rapidly digested into glucose. Larger quantities—more commonly found in drink powders, gummies, meal replacements and sports supplements—can therefore raise blood glucose quickly. This may be more relevant if you have diabetes, insulin resistance or are deliberately limiting rapidly absorbed carbohydrates.

You may also encounter claims that maltodextrin damages the gut microbiome. Laboratory and animal research has raised legitimate questions about its effects on intestinal bacteria and the protective mucus layer, but convincing evidence of harm in humans at the amounts normally found in supplements remains limited.

Our Verdict

The dose and the type of product matter.

A trace amount used as a carrier is very different from maltodextrin appearing near the top of the ingredient list in a flavoured powder. Nevertheless, it provides little nutritional value and is often included primarily because it makes manufacturing cheaper or easier.

We do not believe maltodextrin needs to be treated as a poison. We simply prefer supplements that deliver meaningful active ingredients without using it when it serves no genuine purpose.

At Arbor Vitamins, none of our formulas contain maltodextrin.

Read our complete guide to maltodextrin in supplements →

Talc (E553b) in Supplements: Should You Be Concerned?

Talc is a naturally occurring mineral composed mainly of hydrated magnesium silicate. On a supplement label, it may appear as talc or E553b.

Manufacturers use it as a:

• Flow agent to help powders move through machinery

• Lubricant to prevent tablets sticking during production

• Anti-caking agent

• Coating or polishing agent for tablets

It does not provide a meaningful nutritional benefit.

Does Talc in Supplements Cause Cancer?

In 2024, the International Agency for Research on Cancer classified talc as “probably carcinogenic to humans” — Group 2A. This classification deserves attention, but it needs to be interpreted correctly.

IARC classifications identify whether something is capable of causing cancer under certain circumstances. They do not measure the risk created by a particular dose, exposure route or finished product. The available human evidence was limited and largely concerned ovarian cancer, occupational exposure and the use of talc-based body powders—not the ingestion of small quantities in supplements.

There is currently no convincing evidence that the amount of food-grade talc found in a typical tablet or capsule causes cancer.

What About Asbestos Contamination?

Talc deposits can occur close to asbestos in the ground, making contamination a legitimate quality-control concern. Talc intended for food or pharmaceutical use must meet relevant purity standards, but this makes responsible sourcing and testing particularly important.

This should not be interpreted as meaning that every supplement containing talc is contaminated with asbestos. It does, however, explain why some consumers and manufacturers prefer to avoid the ingredient altogether.

Our Verdict

There is no need to panic if you discover talc on a supplement label. The evidence does not show that occasional oral exposure from a properly manufactured supplement will cause harm.

However, talc adds no nutritional value, questions remain around long-term exposure, and alternative manufacturing methods are available. We therefore see little reason to include it when a supplement can be made successfully without it.

Arbor Vitamins does not use talc in any of its formulations.

Titanium Dioxide (E171): Why Is It Used in Supplements?

Titanium dioxide is a white pigment. In supplements, it may be added to tablet coatings or capsule shells to make them look brighter, whiter and more uniform.

On a label, it may appear as:

• Titanium dioxide

• TiO₂

• E171

• Colour: titanium dioxide

It has no nutritional benefit and does not improve the effectiveness, absorption or stability of the active ingredients. Its purpose is overwhelmingly cosmetic.

Is Titanium Dioxide Banned?

The answer depends on where the product is made and sold.

In 2021, the European Food Safety Authority concluded that titanium dioxide could no longer be considered safe as a food additive because a potential genotoxic effect could not be ruled out. Genotoxicity refers to the ability of a substance to damage genetic material.

This did not prove that titanium dioxide causes DNA damage at the amounts found in supplements. It meant that the available evidence was not strong enough to exclude the possibility.

Titanium dioxide was subsequently removed from the list of permitted food additives in the European Union and is no longer permitted in food supplements manufactured under EU rules, including those in Northern Ireland.

It currently remains authorised as a food additive in Great Britain. Following its own review, the UK Committee on Toxicity concluded that current dietary exposure to food-grade titanium dioxide is unlikely to present a health risk. The Committee nevertheless acknowledged continuing uncertainties around its nanoparticle content and the available evidence.

Our Verdict

The disagreement between regulators does not mean that one side has proved titanium dioxide dangerous and the other has proved it harmless. It reflects different interpretations of incomplete evidence.

For consumers, the more practical question is whether a supplement needs titanium dioxide at all.

Because it is used principally to improve appearance—and provides no nutritional or functional benefit—we see no compelling reason to include it in a daily supplement when uncoloured capsules and alternative coatings are readily available.

None of Arbor Vitamins’ supplements contain titanium dioxide.

Silicon Dioxide (E551): Is It Safe in Supplements?

Silicon dioxide—also called silica or E551—is commonly used as an anti-caking and flow agent. It helps powdered ingredients move through manufacturing equipment and prevents them clumping when exposed to moisture.

It may be added directly by the manufacturer, but it can also arrive as part of a prepared vitamin, mineral or botanical ingredient supplied by another company.

Is Silicon Dioxide the Same as Crystalline Silica?

No. This is an important distinction.

The occupational lung diseases associated with silica exposure are primarily linked to repeatedly inhaling fine crystalline silica dust, particularly in industries such as mining, construction and stone cutting.

Food-grade silicon dioxide is generally amorphous silica. It has a different physical structure and is consumed rather than inhaled, so evidence about occupational crystalline-silica exposure should not be used to claim that silicon dioxide in a capsule causes the same harm.

What About Nanoparticles?

Some food-grade silicon dioxide contains particles or particle structures within the nanoscale range. This has led to reasonable questions about absorption, accumulation and whether conventional safety testing adequately accounts for particle size.

However, after reviewing the available evidence—including nanoscale considerations—the European Food Safety Authority concluded in 2024 that silicon dioxide does not raise a safety concern at its reported uses and exposure levels. It remains an authorised food additive in both the UK and European Union.

There is also no convincing human evidence that the small quantities used in supplements prevent nutrients being absorbed.

Our Verdict

Silicon dioxide has no meaningful nutritional benefit, but current evidence does not support describing it as toxic or placing it on a universal “must avoid” list.

If a manufacturer can produce a stable supplement without adding it, leaving it out may result in a simpler ingredient list. Its presence in a small quantity, however, is not by itself a reason to reject an otherwise well-formulated product.

The more useful questions are how much is present, why it is needed and whether it has been added directly or forms part of an active-ingredient preparation.

Microcrystalline Cellulose (MCC): Filler or Red Flag?

Microcrystalline cellulose—usually shortened to MCC and sometimes listed as E460(i)—is a purified form of plant-derived cellulose.

It is commonly used in tablets and capsules as a:

• Bulking agent when the active dose is too small to fill the product

• Binder to help compressed tablets hold their shape

• Flow agent during manufacturing

• Disintegrant to help a tablet break apart after swallowing

Despite its name, microcrystalline cellulose is not a microplastic. It is an insoluble carbohydrate fibre, usually produced from purified wood pulp or cotton.

Is Microcrystalline Cellulose Safe?

Microcrystalline cellulose is minimally absorbed and largely passes through the digestive system. Following its safety review, the European Food Safety Authority concluded that cellulose additives did not present a safety concern at their reported uses and considered that a numerical acceptable daily intake was unnecessary.

Claims that MCC routinely damages the gut, blocks nutrient absorption or accumulates dangerously in the body are not supported by convincing human evidence.

As with other poorly digested fibres, large quantities may cause bloating, discomfort or changes in bowel movements in some people. The much smaller amount found in an individual supplement is unlikely to cause these effects for most users, although individual sensitivities can occur.

Is MCC the Same as a Vegetable Capsule?

No.

Many plant-based supplement shells are made from hydroxypropyl methylcellulose (HPMC), another cellulose-derived material. HPMC forms the capsule itself, whereas MCC is normally added to the contents as a powder.

They share a plant-cellulose origin but perform different jobs. A supplement can therefore be free from MCC while still using an HPMC capsule shell.

Our Verdict

Microcrystalline cellulose is not inherently dangerous, and its presence does not automatically make a supplement poor quality.

The better question is whether it is being used for a genuine formulation reason or simply to bulk out a product. Excessive MCC can increase tablet size or occupy space that might otherwise be used for active ingredients.

At Arbor Vitamins, we use plant-based HPMC capsule shells where required, but we do not add microcrystalline cellulose as a bulking agent.

Microcrystalline Cellulose (MCC): Filler or Red Flag?

Microcrystalline cellulose—usually shortened to MCC and sometimes listed as E460(i)—is a purified form of plant-derived cellulose.

It is commonly used in tablets and capsules as a:

• Bulking agent when the active dose is too small to fill the product

• Binder to help compressed tablets hold their shape

• Flow agent during manufacturing

• Disintegrant to help a tablet break apart after swallowing

Despite its name, microcrystalline cellulose is not a microplastic. It is an insoluble carbohydrate fibre, usually produced from purified wood pulp or cotton.

Is Microcrystalline Cellulose Safe?

Microcrystalline cellulose is minimally absorbed and largely passes through the digestive system. Following its safety review, the European Food Safety Authority concluded that cellulose additives did not present a safety concern at their reported uses and considered that a numerical acceptable daily intake was unnecessary.

Claims that MCC routinely damages the gut, blocks nutrient absorption or accumulates dangerously in the body are not supported by convincing human evidence.

As with other poorly digested fibres, large quantities may cause bloating, discomfort or changes in bowel movements in some people. The much smaller amount found in an individual supplement is unlikely to cause these effects for most users, although individual sensitivities can occur.

Is MCC the Same as a Vegetable Capsule?

No.

Many plant-based supplement shells are made from hydroxypropyl methylcellulose (HPMC), another cellulose-derived material. HPMC forms the capsule itself, whereas MCC is normally added to the contents as a powder.

They share a plant-cellulose origin but perform different jobs. A supplement can therefore be free from MCC while still using an HPMC capsule shell.

Our Verdict

Microcrystalline cellulose is not inherently dangerous, and its presence does not automatically make a supplement poor quality.

The better question is whether it is being used for a genuine formulation reason or simply to bulk out a product. Excessive MCC can increase tablet size or occupy space that might otherwise be used for active ingredients.

At Arbor Vitamins, we use plant-based HPMC capsule shells where required, but we do not add microcrystalline cellulose as a bulking agent.

Artificial Colours, Flavours and Sweeteners

Colours, flavourings and sweeteners are most common in gummies, chewable tablets, powders and effervescent supplements. They can improve appearance and make unpleasant-tasting ingredients easier to consume, but they do not increase the nutritional value of the product.

Are Artificial Sweeteners Dangerous?

Approved sweeteners are subject to safety assessments and maximum permitted exposure levels. For example, the European Food Safety Authority reassessed sucralose in 2026 and concluded that it remains safe at its currently authorised uses.

Research continues into how different sweeteners may affect appetite, glucose responses and the gut microbiome. Results are not consistent enough to claim that every sweetener causes harm, and findings from high-dose animal or laboratory studies should not be applied directly to the small amounts found in supplements.

Individual tolerance still matters. Some people experience headaches, digestive symptoms or dislike the lingering taste of particular sweeteners. People with phenylketonuria must avoid aspartame because it contains a source of phenylalanine.

Our Verdict

Taste-masking ingredients can serve a genuine purpose in a powder, liquid or chewable supplement. A swallowed capsule, however, rarely needs to be brightly coloured, flavoured or sweetened.

These additives should not all be described as toxic. Nevertheless, if they provide no functional benefit and can be left out without making the supplement difficult to take, a shorter ingredient list is usually preferable.

Arbor Vitamins does not add artificial colours, flavourings or sweeteners to its formulations.

How to Read a Supplement Label in 60 Seconds

A long ingredient list is not automatically bad, and a short one is not automatically good. The aim is to understand what you are taking, how much you are taking, which forms are used and what else has been added.

Use this quick label check before buying:

Four Questions Every Label Should Answer

Before buying, you should be able to answer:

1. What are the active ingredients?

2. How much will I receive in the full daily serving?

3. Which chemical or botanical forms have been used?

4. What else is inside the capsule, tablet, gummy or powder?

If the packaging makes these questions difficult to answer, the problem is not necessarily the formulation—it is the lack of transparency.

Terms such as “clean”, “natural”, “premium” and “high strength” have little value unless the label provides enough information to verify them.

How Arbor Vitamins Approaches Excipients

Our position is not that every excipient is harmful. It is that every ingredient—active or otherwise—should have a clear and defensible reason for being included.

A supplement cannot always consist solely of loose active ingredients. A capsule needs a shell, some delivery systems require particular materials, and certain formulations may need help remaining stable. The aim should therefore be purposeful formulation, not an unrealistic claim that every non-active ingredient is dangerous.

A Note About Silica

TRINITY contains bamboo silica extract as an intentional source of silica. This is not the same as adding silicon dioxide (E551) as an anti-caking agent.

The ingredient name alone is therefore not enough. Its source, form, quantity and reason for inclusion all matter.

Clean Formulation Without Fearmongering

We do not describe every permitted additive as a toxin, and we do not believe that discovering a small amount of an approved excipient should cause panic.

Our approach is simpler:

If an ingredient improves the formulation or delivery of the supplement, it should be disclosed and justified. If it is present only for manufacturing convenience or cosmetic appeal, we would rather leave it out.

Arbor Vitamins’ formulations are developed by a clinical pharmacist with particular attention to nutrient form, compatibility, timing and label transparency.

Which Supplement Fillers Should You Avoid?

There is no scientifically defensible blacklist that applies to every person and every supplement. Some excipients are unnecessary but low risk; others are useful in particular formats; and a small number deserve greater caution because of unresolved evidence or individual health considerations.

The Short Answer

If you want a cleaner supplement, prioritise avoiding:

• Titanium dioxide and purely cosmetic colours

• Large quantities of maltodextrin used to bulk powders

• Poorly disclosed proprietary blends

• Unnecessary fillers that dominate the ingredients list

• Any excipient to which you have a known allergy or intolerance

Do not assume that a long chemical name means an ingredient is dangerous—or that a “natural” alternative is automatically safer.

The best supplement is not necessarily the one with the shortest label. It is the one that provides appropriate active ingredients in transparent doses, with no more supporting ingredients than the formulation genuinely requires.

Frequently Asked Questions About Supplement Fillers and Excipients

What is an excipient in a supplement?

An excipient is an ingredient included for a reason other than providing the supplement’s intended nutritional benefit. Excipients may help fill capsules, bind tablets, prevent powders clumping, improve stability, create a coating or make a product taste and look more appealing.

Are fillers in supplements bad for you?

Most approved fillers are not considered harmful in the small quantities normally used. However, they may be unnecessary, poorly tolerated by some people or used primarily for manufacturing convenience. Each ingredient should be assessed according to its function, quantity and available safety evidence.

What are the worst fillers in vitamins?

Titanium dioxide, unnecessary artificial colours and large quantities of maltodextrin are reasonable ingredients to avoid because they offer little nutritional benefit. Poorly disclosed proprietary blends are also a concern because they prevent you judging whether individual active ingredients are meaningfully dosed.

Does magnesium stearate stop supplements being absorbed?

There is no convincing human evidence that the small amount of magnesium stearate used in supplements meaningfully prevents nutrient absorption. Formulation studies show that excessive quantities or prolonged mixing can affect how quickly some tablets dissolve, but this does not prove that normal use blocks absorption in the body.

Is silicon dioxide safe in supplements?

Current evidence indicates that food-grade amorphous silicon dioxide is safe at permitted exposure levels. It is not the same as the inhaled crystalline silica dust associated with occupational lung disease. Its presence in a small quantity is not, by itself, a major warning sign.

Are capsules better than tablets for avoiding fillers?

Capsules often require fewer binders and coatings than compressed tablets, but they are not automatically filler-free. Always check the complete ingredients list. The capsule shell itself—commonly HPMC or gelatine—is a functional excipient rather than an active nutrient.

Can supplement excipients cause allergic reactions or intolerance?

Yes, although serious reactions are uncommon. Ingredients such as lactose, soya-derived materials, certain colours and other processing aids may be unsuitable for particular individuals. Stop taking the product and seek appropriate medical advice if you suspect a reaction.

How can I find supplements without unnecessary fillers?

Look for a complete ingredients list, clearly stated active quantities and named nutrient forms. Avoid relying solely on terms such as “clean” or “natural”. A transparent manufacturer should explain what each non-active ingredient does and why it is needed.

Are “natural” excipients always better?

No. Natural origin does not guarantee safety, tolerability or quality. Talc is naturally occurring, for example, while many well-tolerated capsule materials are manufactured from modified plant cellulose. Function, purity and evidence matter more than whether an ingredient sounds natural.

Final Thoughts: Choosing Supplements Without Unnecessary Fillers

An unfamiliar ingredient is not automatically harmful, and an approved additive is not automatically necessary.

When comparing supplements, focus on four things:

1. Are the active ingredients clearly identified?

2. Are their individual quantities disclosed?

3. Are the forms appropriate for the intended use?

4. Does every additional ingredient have a reasonable function?

Magnesium stearate, silicon dioxide and microcrystalline cellulose are frequently portrayed as toxic online, but current evidence does not support many of the strongest claims made about them.

That does not mean formulation quality is irrelevant. Titanium dioxide, cosmetic colours, large quantities of maltodextrin and excessive bulking agents may add little value. Where simpler alternatives are available, choosing a product without them is entirely reasonable.

The goal is not to fear every excipient. It is to demand better labels, purposeful formulations and enough transparency to make an informed choice.

Continue Reading

• Supplements Without Magnesium Stearate: What It Is and Why It Is Used

• Maltodextrin in Supplements: What It Is and Whether It Is Bad

• The Science of Nutrient Compatibility

• When Should You Take Supplements? The Science of Nutrient Timing

References

1. European Food Safety Authority. Re-evaluation of sodium, potassium and calcium salts of fatty acids and magnesium salts of fatty acids.

2. Hofman DL, van Buul VJ and Brouns FJPH. Nutrition, health and regulatory aspects of digestible maltodextrins.

3. International Agency for Research on Cancer. IARC Monographs Volume 136: Talc and Acrylonitrile.

4. European Food Safety Authority. Safety assessment of titanium dioxide (E171) as a food additive.

5. UK Committee on Toxicity. Statement on the safety of titanium dioxide (E171) as a food additive.

6. European Food Safety Authority. Re-evaluation of silicon dioxide (E551) as a food additive.

7. European Food Safety Authority. Re-evaluation of celluloses, including microcrystalline cellulose.

8. Food Standards Agency. Food additives and colours associated with activity and attention in children.

9. European Food Safety Authority. Re-evaluation of sucralose (E955) as a food additive.

Written and reviewed by Jon Wright, Clinical Pharmacist and co-founder of Arbor Vitamins.
Last reviewed: August 2026.

This article provides general information and is not a substitute for individual medical advice. Speak to a doctor or pharmacist before starting a supplement if you take medication, have a medical condition, or are pregnant or breastfeeding.