What are the best clean supplements?

Read the list backwards: the six lines that follow the active, what each one is for, why each is permitted, and why each is still reasonably unwanted by someone

What are the best clean supplements is a question answered by a reading habit rather than a product list, and the habit is to read the ingredient list backwards, because the first line is the active, which is what the product is, and every line after it is what clean is actually about. A capsule has six kinds of line after its active, and knowing what each is for turns a vague wish for cleanliness into a specification. Line one is the bulking agent: a capsule has a fixed volume and most actives do not fill it, so rice flour, microcrystalline cellulose or maltodextrin tops it up; the bulking agent is inert, is the largest excipient by weight, and is the line a buyer with a rice, grain or corn concern reads first. Line two is the flow agent: powders clump and stick in an encapsulating machine, and magnesium stearate, a salt of a fatty acid, or silicon dioxide, a form of silica, lets the powder run; both are used at fractions of a per cent, both have been assessed by the regulator as safe at those levels, and magnesium stearate in particular has a folklore of harm online that the assessment does not support, though a buyer may still prefer a capsule without it. Line three is the shell: hydroxypropyl methylcellulose, a plant cellulose, or gelatine, from animal collagen, and this is the line that decides whether a capsule is vegan, vegetarian, halal or kosher, which is the most common reason a buyer reads the list at all. Line four is the colour: titanium dioxide, used to whiten a capsule or coat a tablet, which the EU withdrew from food in 2022 and which Great Britain, after its own food safety assessment, has continued to permit, so that a UK product may lawfully contain it; iron oxides, which colour a capsule brown or red; or no colour at all, which is the line a buyer who dislikes a whitened capsule looks for. Line five, in a powder, is the sweetener and flavour: sucralose, acesulfame K or stevia, and a flavouring, which is where a protein powder's long list comes from and which a buyer avoiding sweeteners reads to the end. Line six, on a tablet, is the coating: a glaze or a film that makes it swallowable and protects it from moisture, which a capsule does not need.

Every one of those lines is a permitted food additive on the retained additives regulation, with an E number, a list of the foods it may be used in and a maximum level, and every one has been assessed by the regulator as safe at the levels a supplement uses, which is the fact that the word clean tends to obscure: an excipient is not a contaminant, and a product with six excipient lines is not less safe than a product with one. What is true is that each line is reasonably unwanted by someone for a reason of their own, allergy to a bulking agent's source, veganism or religion for the shell, a preference against colour or sweetener, or simply a liking for a short list, and the word clean is the name a buyer gives to that reason. Clean has no definition in UK food law: it is not a nutrition claim, it is not a health claim, and a brand may not use it to imply that its product is healthier or safer, since a safety comparison between two permitted formulations is a claim with nothing behind it. It is therefore a specification the buyer writes, two or three lines of what they want absent and why, and the ingredient list read backwards is checked against it.

The specification written, the list checked against it, the loud clean product and what it is charging for, and the dull list that wins

Writing the specification takes a minute and makes the shelf legible. A vegan lifter writes: no gelatine shell, no animal-derived glaze. A lifter with a grain concern writes: no rice flour or maltodextrin bulking agent, cellulose acceptable. A lifter who dislikes a whitened capsule writes: no titanium dioxide. A lifter avoiding sweeteners writes: unflavoured powders only. A lifter who simply wants a short list writes: active, shell and one bulking agent, nothing else. Each specification is checked against the list read backwards in the time it takes to turn the tub, and the product either meets it or does not, with no need for the adjective at all. Two things the specification does not do are worth saying. It does not make a product more effective, since the active is the first line and the excipients do nothing to it; a clean magnesium delivers the elemental dose on its label and a six-excipient magnesium delivers the elemental dose on its label, and the number that matters is the elemental one. And it does not replace the quality checks, identity, purity, potency and consistency, which are about what is in the active rather than what is beside it; a product with a three-line list and no batch certificate is clean by a buyer's specification and untested by any laboratory's, and the second fact matters more.

The loud clean product is the one to read most carefully, because the adjective has a price and the price is usually for the adjective. A product that advertises its cleanliness on the front of the tub, in its name and across its listing is making a comparison with other permitted formulations that it may not lawfully make as a health claim, is often charging two or three times the category's pence per day, and when its list is read backwards usually turns out to contain the same shell, bulking agent and flow agent as the product beside it, with the word doing the work the list does not. The honest observation, after enough tubs have been turned, is that the cleanest list is usually the dullest one: an active, a shell and a bulking agent, three lines, no colour, no coating, no sweetener, which is what a capsule needs to exist and nothing more, and which most products advertising cleanliness could have and most do not. The worked example is that list without the adjective: {FL}, magnesium bisglycinate, an HPMC shell and rice flour, three lines, no colour, no coating, no proprietary blend, 1500mg of the compound stated as 300mg elemental at 80% NRV, batch tested for lead, mercury, arsenic and cadmium with the certificate on request, UK made under GMP and BRC, 180 capsules for £19.99 at 22p a day, vegan by the shell and short by the list, and sold without the word clean anywhere on it because the word is the buyer's to write and the list is the brand's to print. The best clean supplements are the ones whose lists, read backwards, meet the specification a buyer wrote for themselves, and they are rarely the ones that say so.

What to check on the label

Questions people also ask

What does a clean supplement actually mean?

Nothing in UK food law, where clean is neither a nutrition claim nor a health claim and may not be used to imply a product is healthier or safer than another permitted formulation; in practice it is a buyer's specification about the lines after the active, the bulking agent, flow agent, shell, colour, sweetener and coating, each a permitted food additive assessed as safe at the levels used, and each reasonably unwanted by a particular buyer for allergy, veganism, religion or a preference for a short list; the list read backwards against the specification is the whole method.

Is magnesium stearate bad for you?

Not by the regulator's assessment; it is a salt of stearic acid, a fatty acid found in most foods, used as a flow agent at fractions of a per cent of a capsule so the powder runs through the encapsulating machine, and it is a permitted additive with a maximum level that a supplement uses a small part of; the online folklore about it blocking absorption or harming immunity is not supported by the assessment or by trials, though a buyer who prefers a capsule without it is entitled to write that into their specification and to find products that meet it.

Is titanium dioxide allowed in UK supplements?

Yes; the EU withdrew titanium dioxide from food in 2022 after its own agency could not rule out a concern about genotoxicity, while Great Britain's food safety assessment reached a different conclusion and the additive remains permitted in UK food and supplements as a whitener for capsules and tablet coatings; a buyer who would rather not have it reads the colour line of the list for the E number or the name and chooses an uncoloured capsule, which most products with a short list are.

Are clean supplements more effective?

No; the excipients after the active do nothing to it, so a magnesium with three lines delivers the elemental dose on its label exactly as a magnesium with nine lines does, and the number that decides effectiveness is the elemental dose against the NRV rather than the length of the list; clean is a specification about what a buyer wants absent for their own reasons, and it is separate from the quality tests, identity, purity, potency and consistency, which concern the active itself and which a short list does not replace.

What is the cleanest form of supplement to take?

By the list, a capsule with three lines: the active, a shell and one bulking agent, no colour, coating, sweetener or flavour, which is what a capsule needs to exist and nothing more; a tablet needs a coating and binders, a flavoured powder needs sweeteners and flavourings, and a gummy needs sugar, gelatine or pectin and colour, so a capsule with an HPMC shell is the shortest honest list for most actives, and the shortest list is usually the dullest tub on the shelf rather than the one with the word on the front.

Sources

1. Retained Regulation (EC) No 1333/2008 on food additives: the permitted additives, their E numbers, the foods they may be used in and their maximum levels, the list that decides which anti-caking agents, colours, sweeteners and glazing agents may appear in a food supplement sold in Great Britain. https://www.legislation.gov.uk/eur/2008/1333/contents
2. The pharmaceutical excipient literature: capsule shells, bulking agents, glidants and anti-caking agents, binders, disintegrants and coatings are functional non-active ingredients whose purpose is manufacturability, stability and dosing accuracy rather than effect. PubMed record
3. The titanium dioxide reviews: the EU withdrew authorisation of E171 as a food additive in 2022, while the UK's Food Standards Agency conducted a separate review and it remains permitted in Great Britain, with manufacturers increasingly reformulating away from it. https://www.food.gov.uk/news-alerts/news/titanium-dioxide
4. The clean label literature: clean label is a consumer and marketing concept with no regulatory definition, generally taken to mean short ingredient lists, recognisable ingredients and the absence of artificial additives. PubMed record

Related answers

• What are the best third party tested supplements?
• Are Amazon supplements 3rd party tested?
• Are NOW supplements on Amazon legit?
• What are the best made supplements?
• Which supplements are approved by Informed Sport?
• Which supplements are Informed Sport certified?