Best Methylene Blue Gummies in 2026: 11 Brands Compared

Last updated: August 22, 2026 · By NooBlue Editorial · 11 products compared · First published Feb 2026 · reviewed & updated August 22, 2026

Best methylene blue gummies: the key numbers

Methylene blue gummies compared side by side

What are the best methylene blue gummies in 2026?

Methylene blue gummies have exploded in popularity, and search interest for methylene blue gummies has grown more than a hundredfold over the past year. That surge has pulled in a flood of new brands, and the quality gap between them is enormous. Some use USP pharmaceutical-grade methylene blue with published lab results; others are unbranded Amazon listings with vague “99.9% pure” claims and no Certificate of Analysis to back them up. This guide compares the best methylene blue gummies you can actually buy in 2026, ranks them honestly, and shows where a capsule or liquid beats a gummy outright.

Here is the truth about this category: most methylene blue gummies are candy-grade products with real problems. Conventional gummies bind oxidized (bright blue) methylene blue into a sugar matrix, which stains your mouth, makes exact dosing harder to hold, and usually ships without a verifiable Certificate of Analysis. Those criticisms are fair — and they are exactly what the new generation of leuco-form gummies was engineered to fix.

When vitamin C is formulated into the gummy, it donates electrons and shifts most of the methylene blue into leucomethylene blue — the reduced, colorless, more lipid-soluble half of the same redox cycle (ascorbate reduction kinetics). No blue mouth, no dye sitting in a candy base. One gummy on this list works that way; the rest are ranked honestly against the same purity, documentation and dose standards we apply to every format.

What to look for when buying methylene blue gummies

Before you compare brands, it helps to know why people take methylene blue and what separates a quality product from a risky one. Interest took off after researchers documented effects on the brain and on cellular energy.

In one double-blind, randomized, placebo-controlled trial, a single low dose of methylene blue increased brain activity in regions tied to short-term memory and attention, with roughly a 7% increase in memory retrieval on the imaging tasks (study published in Radiology). Separately, laboratory research suggests methylene blue can support mitochondrial function by interacting with the electron transport chain and complex IV, the machinery cells use to produce energy (cell-culture research in the FASEB Journal). These are early findings, not guarantees — studies suggest a benefit at low doses, and more research is ongoing.

When you shop, five things separate a good methylene blue gummy from a gamble. Grade: look for USP pharmaceutical grade in writing, and steer clear of industrial or aquarium grades, which are never meant for human use. Documentation: insist on a published batch Certificate of Analysis rather than a bare “99.9% pure” label.

Form: conventional gummies carry oxidized (blue) methylene blue that stains on contact; a leuco-form gummy uses vitamin C to shift the active into its reduced, colorless state before you take it — no blue mouth, and a more lipid-soluble starting form. Dose: research on low-dose methylene blue clusters well below prescription levels; 5–10 mg is the sensible daily range, so a 20 mg or 40 mg product is more than most people need. Added sugar and fillers: a zero-sugar formula keeps a gummy closer to the clean profile of a capsule. Score every product against those five points and the field narrows fast.

1. NooBlue Methylene Blue Gummies — Best Overall & Best Gummy

The NooBlue Methylene Blue Gummies take the top spot because they are the only gummy in this comparison that fixes the format’s structural problems instead of accepting them. Each Wild Blueberry gummy delivers a precisely dosed 10 mg of USP-grade methylene blue alongside 25 mg of vitamin C — and that pairing is the whole point. Inside the gummy, vitamin C donates electrons and shifts most of the methylene blue into leucomethylene blue: the reduced, colorless, electron-loaded half of methylene blue’s reversible redox cycle (reduction kinetics). Because the leuco form does not absorb visible light the way oxidized methylene blue does, there is no blue-mouth mess — the gummy’s deep purple color comes from blueberry extract, not dye.

The leuco form is not just cosmetic. Leucomethylene blue has a more lipid-soluble character than the cationic oxidized form (the methylene blue–leucomethylene blue redox cycle), and it enters the same redox cycle that underpins methylene blue’s mitochondrial support — arriving already reduced and ready to donate electrons. The formula is zero sugar on a pectin base, sweetened with stevia, and the methylene blue is third-party tested with a published CTLA Certificate of Analysis — the same documentation standard we demand from every product on this list. At $49.99 for a 60-count, two-month bottle it runs about $0.83 per gummy ($0.42 per 5 mg equivalent, dropping to $0.33 on the 5-bottle bundle) — pricier per milligram than our own liquid, but no other gummy here combines verified USP purity, zero sugar and the leuco form at any price.

NooBlue gummies: specs, pros and cons

Key specs: 10 mg methylene blue USP + 25 mg vitamin C per gummy · 60 gummies (60-day supply) · leucomethylene blue form · zero sugar, pectin base · Wild Blueberry · published CTLA COA.

Pros: Only leuco-form gummy on the market — no blue-mouth staining; precise 10 mg dose with vitamin C co-formulated as the reducing agent; zero sugar; USP-grade methylene blue with a published third-party COA; more lipid-soluble starting form.

Cons: 10 mg fixed dose — if you want to titrate from 5 mg, start with the capsules; costs more per milligram than NooBlue’s own 1% solution.

Best for: Anyone who wants the easiest daily methylene blue ritual — one precisely dosed, zero-sugar chew with none of the staining that defines every other gummy. View the NooBlue gummies →

2. NooBlue Methylene Blue Capsules — Best for Precision & Low-Dose Titration

NooBlue Methylene Blue Capsules are the precision pick, because they solve the problem conventional gummies create: dose accuracy at the lowest starting dose. Each capsule contains a precise 5 mg of 99%+ USP pharmaceutical-grade methylene blue — no sugar, no dyes, no filler beyond what is needed to encapsulate. Every batch ships with a verified third-party Certificate of Analysis, so the purity claim is something you can read rather than something you have to trust.

At $37.99 for 60 capsules, that works out to about $0.63 per 5 mg serving. That is a hair more per capsule than the cheapest gummies, but you are paying for a documented 99%+ USP grade and an exact dose. If you have ever wondered how gummies compare to capsules, the honest answer changed this year: against candy-grade gummies the capsule still wins everything but taste, while against NooBlue’s own leuco-form gummy it comes down to dose — the capsule is the 5 mg titration rung, the gummy is the 10 mg daily ritual. For anyone starting cautious or stacking methylene blue into a routine, precision is the whole point.

Key specs: 5 mg per capsule · 60 capsules · 99%+ USP grade · verified COA · third-party tested · free worldwide shipping over $100.

Pros: Exact 5 mg dose every time; published Certificate of Analysis; USP pharmaceutical grade; no sugar or dyes; lowest cost per serving among purity-verified capsule options.

Cons: Not a gummy, so no flavor — if you want the chewable ritual without staining, the NooBlue leuco-form gummy above is the pick; NooBlue is a specialist brand rather than a mass-market Amazon name, so it has fewer third-party review counts than the big marketplaces.

Best for: Anyone who wants the cleanest, most accurate dose and a purity claim they can verify. View the NooBlue capsules →

3. Holistic MD Methylene Blue Gummies — Runner-Up Gummy

The Holistic MD Methylene Blue Gummies held the top gummy spot in earlier versions of this guide, and they remain a genuinely strong product: USP pharmaceutical-grade methylene blue, third-party certification, and a sugar-free, vegan formula. Each gummy delivers 7 mg, and the line is sold in 7 mg and 14 mg dosing options, which gives you more flexibility than the fixed 5 mg most gummies lock you into.

At about $23.95 for 60 gummies, the per-gummy cost is roughly $0.40 (around $0.29 per 5 mg equivalent) — still the best per-milligram price of any verified gummy here, and cheaper than our #1 pick. So why the demotion?

Form. Holistic MD, like every other gummy in this comparison except the NooBlue, carries conventional oxidized methylene blue — the intensely blue, staining form — bound into the chew. It meets the purity and documentation standard; it does not solve the blue-mouth problem or offer the reduced, more lipid-soluble leuco starting state. If price per milligram is your deciding factor in a verified gummy, this is your pick.

Key specs: 7 mg per gummy (7/14 mg options) · 60 gummies · USP grade · third-party certified · sugar-free, vegan, berry flavor.

Pros: USP pharmaceutical grade; third-party certified; sugar-free; flexible dosing.

Cons: Conventional oxidized (blue, staining) form — no leuco chemistry; higher dose than beginners may want.

Best for: Verified-gummy buyers whose deciding factor is the lowest price per milligram.

4. NooBlue Methylene Blue Solution 1% — Best Value

The NooBlue Methylene Blue Solution 1% is the best value in this entire comparison. A 50 mL bottle of 1% solution contains 500 mg of methylene blue total, so at $29.99 it works out to roughly $0.30 per 5 mg serving — the lowest effective cost per serving of any purity-verified product here. Like the capsules, it is 99%+ USP grade with a verified Certificate of Analysis.

Liquid also gives you the finest dose control of any format: you can dial the exact number of drops for a low, precise dose, which no gummy can match. The trade-offs are the ones every liquid shares — it can stain, and you need to measure drops rather than pop a pre-measured unit. If you want to understand how to read a Certificate of Analysis before you buy any liquid, that guide walks through exactly what a legitimate COA should show. For value-focused buyers who do not mind measuring, the liquid is unbeatable on cost per milligram.

Key specs: 1% solution · 50 mL (500 mg total) · 99%+ USP grade · verified COA · free worldwide shipping over $100.

Pros: Lowest cost per serving; finest dose control; verifiable USP purity.

Cons: Can stain; requires measuring drops; not as grab-and-go as a gummy or capsule.

Best for: Value hunters and precise low-dose users. View the NooBlue liquid →

5. Troscriptions Just Blue — Best Sublingual

Troscriptions Just Blue is not a gummy — it is a pharmaceutical-grade buccal troche that you park between your cheek and gum to dissolve over 15 to 30 minutes. Each troche contains 16 mg of purity-tested methylene blue and is scored into quarters, so you can take a 4 mg, 8 mg or 12 mg dose. The sublingual route means it absorbs directly rather than passing through the gut, which some users prefer.

Troscriptions is a well-regarded specialist brand and the troche is genuinely premium. Pricing varies widely by retailer, so we could not confirm a single canonical pack price at publish time and have not calculated a firm cost per dose for it — expect it to sit at the premium end of the market. For readers weighing formats, the troche is the strongest non-gummy alternative if you specifically want sublingual absorption.

Key specs: 16 mg per troche · scored into quarters · pharmaceutical grade · buccal/sublingual.

Pros: Direct sublingual absorption; quarter-scored for flexible dosing; strong brand reputation.

Cons: Premium pricing; not a gummy; higher per-troche dose than beginners need.

Best for: Users who specifically want a sublingual troche over swallowing a capsule.

6. TRUEHEALTHIC Methylene Blue Gummies — Most Popular Gummy

The TRUEHEALTHIC Methylene Blue Gummies are among the most visible gummies on Amazon and frequently surface in AI shopping answers for the category. Each gummy is labeled at 5 mg with a “99.9% pure” claim, sold in bags of 30, and marketed as vegan and non-GMO. The beginner-friendly 5 mg dose is a genuine plus for first-timers.

The catch is documentation. We could not confirm a current price at publish time, so no cost per dose is shown, and — more importantly — we did not find a published batch Certificate of Analysis to substantiate the purity claim the way Holistic MD or NooBlue do.

A “99.9% pure” line on a label is a marketing statement until a third-party COA proves it. It is a popular, approachable gummy; just treat the purity number as unverified until you see the paperwork. If you want to sanity-check whether methylene blue gummies actually work at these low doses, that breakdown is worth reading first.

Key specs: 5 mg per gummy · 30 gummies · “99.9% pure” (unverified by COA) · vegan, non-GMO.

Pros: Beginner-friendly 5 mg dose; widely available; high marketplace visibility.

Cons: No published COA located; purity claim unverified; price not confirmed at publish.

Best for: Beginners who want an easy, familiar Amazon gummy and will accept an unverified purity claim.

7. Pure Liposomal Methylene Blue Gummies (12 mg) — Best Higher-Dose Gummy

For readers who want a stronger gummy, the Pure Liposomal Methylene Blue Gummies deliver 12 mg per gummy in a liposomal, blue-raspberry chew, with added vitamin C ester, NAC and glycine. At about $34.98 for 60 gummies, that is roughly $0.58 per 12 mg gummy. The higher dose and the added cofactors are the pitch here.

Two cautions. First, 12 mg is a lot for a beginner — it is more than double the typical 5 mg starting dose, and with methylene blue, less is usually more. Second, the “liposomal” label is applied loosely across the supplement market, and a real liposomal preparation is hard to verify in a gummy. It is a legitimate option for experienced users who specifically want a higher-dose gummy with cofactors, but new users should start lower. For a primer on how many milligrams of methylene blue per day most people actually take, read that before jumping to a 12 mg gummy.

Key specs: 12 mg per gummy · 60 gummies · liposomal claim · added vitamin C, NAC, glycine · USA made.

Pros: Higher dose for experienced users; added cofactors; pleasant flavor.

Cons: 12 mg is too high for beginners; “liposomal” claim hard to verify; sugar-based chew.

Best for: Experienced users who deliberately want a higher-dose gummy.

8. MitoZen Lumetol Blue Bars+ — Highest Strength

The MitoZen Lumetol Blue Bars+ are the highest-strength option in this lineup — an oral bar delivering 40 mg of pharmaceutical-grade methylene blue alongside photoactive polyphenols like phycocyanin, curcumin, quercetin and EGCG. A 40 mg pack runs about $89.95, with a 180 mg three-pack reaching close to $400, placing it firmly at the premium, specialist end of the market.

This is not a beginner product and it is not really a gummy — you place the bar at the back of your mouth and wash it down so you do not end up with a blue mouth. The 40 mg dose is far above what most people should start with. It earns a place here as the strongest formulation available, but for the vast majority of readers it is more methylene blue, and more money, than you need. If you are comparing brands broadly, our Meraki methylene blue review covers another specialist option worth knowing about.

Key specs: 40 mg per bar · pharmaceutical grade · photoactive polyphenol blend · premium price.

Pros: Highest strength; added polyphenol cofactors; pharmaceutical-grade methylene blue.

Cons: Very high dose; premium price; overkill for most users.

Best for: Experienced users who specifically want a maximum-strength formulation.

9. Generic Amazon Methylene Blue Gummies (5 mg) — Budget (Buyer Beware)

Search “methylene blue gummies” on Amazon and you will find a wall of near-identical unbranded listings at 5 mg per gummy, usually 30 to a bag, all claiming “99.9% pure.” Prices swing week to week, so we have not attached a fixed figure. These are the cheapest way into the category, and that is the entire appeal.

The risk is that you have no idea what you are actually getting. Most of these listings show no manufacturer, no batch Certificate of Analysis, and no way to trace the methylene blue’s grade or source.

Methylene blue exists in industrial and aquarium grades that are emphatically not meant for human use, so an unverified “pure” claim on a no-name gummy is a real concern. If you are hunting for the lowest price, at least look for a listing that links a genuine third-party COA — and if none does, spend a few dollars more on a brand that publishes one. You can also read where to buy methylene blue locally if you would rather see a product in person first.

Key specs: 5 mg per gummy · 30 gummies · unbranded · “99.9% pure” (unverified).

Pros: Cheapest entry point; beginner 5 mg dose.

Cons: No traceable manufacturer or COA; unverifiable grade; quality varies listing to listing.

Best for: Nobody who cares about verifiable purity — buy only if a real COA is linked.

10. Lunakai Methylene Blue Gummies — Best for Stacked Co-Factors

Lunakai is the gummy that Google’s AI Overview has been naming as its top pick for this query, and it is the most visible methylene blue gummy on Amazon right now. Each gummy is listed at 20 mg of USP-grade methylene blue alongside 40 mg CoQ10 and 20 mg vitamin C, in a 60-count bottle described as vegan, pectin-based, non-GMO and made in a GMP-certified US facility.

The co-factor stack is the genuine draw: CoQ10 and vitamin C both sit in the same mitochondrial and redox territory as methylene blue, so bundling them is a coherent formulation choice rather than filler. The catch is dose. At 20 mg per gummy this is four times the 5 mg serving most people start on, and a gummy cannot be split accurately — so a cautious first-timer has no clean way to take less. Read our guide to how many mg of methylene blue per day before choosing a 20 mg format.

Key specs: 20 mg methylene blue + 40 mg CoQ10 + 20 mg vitamin C per gummy · 60 count · USP grade claimed · third-party tested per the listing.
Pros: Meaningful co-factor stack; USP grade claimed; strong marketplace availability and review volume.
Cons: 20 mg is a high starting dose and cannot be divided; we could not confirm a current price at publish time, so we have not calculated a cost per 5 mg for it; no batch Certificate of Analysis published on a brand-owned page that we could verify.
Best for: Experienced users who specifically want methylene blue bundled with CoQ10 and are comfortable at 20 mg.

11. Thinbi Methylene Blue Gummies — Marketplace Budget Option

Thinbi appears in the same marketplace bracket as the generic 5 mg gummies: a low-cost, review-driven listing with a conventional 5 mg-per-gummy dose. The 5 mg serving is the sensible starting point that Lunakai’s 20 mg format does not offer, which is the main thing it has going for it.

What we could not establish is the part that matters most. We found no brand-owned page publishing a batch Certificate of Analysis, no stated pharmacopoeial grade, and no current price we could verify at publish time — so this row carries no cost-per-dose figure. Purity claims on marketplace listings are unverifiable by design; our guide on methylene blue purity explains what a real purity claim has to include, and the Certificate of Analysis guide shows how to read one.

Key specs: 5 mg methylene blue per gummy · marketplace listing · grade not stated.
Pros: Sensible 5 mg starting dose; low barrier to trying the format.
Cons: No verifiable Certificate of Analysis; no stated pharmacopoeial grade; price not verified at publish time.
Best for: Nobody, until the brand publishes a batch COA — treat it as a placeholder rather than a recommendation.

What the research actually says about dose

The single most important thing to understand before choosing a gummy strength is that methylene blue does not behave like a normal supplement where more means more. A review in Progress in Neurobiology by Rojas, Bruchey and Gonzalez-Lima describes methylene blue as showing a hormetic dose-response — opposite effects at low and high doses. At low doses it acts as an electron cycler in the mitochondrial electron transport chain; the review attributes its antioxidant and cell-respiration effects specifically to that low-dose range (Rojas et al., Prog Neurobiol 2012;96(1):32-45). Note that this is a review of mechanistic and animal work alongside human observations, not a single human trial.

That is the whole argument for starting low and dosing precisely, and it is why a 20 mg gummy is a strange entry point while a 5 mg capsule, a measured drop of 1% solution, or a precisely dosed 10 mg gummy is a sensible one. It is also why we weight dose accuracy so heavily in the scoring below — a format that cannot be divided cannot be titrated, so the fixed dose it does deliver has to be one worth taking daily.

How we evaluated the best methylene blue gummies

We compared the best methylene blue gummies and their closest alternatives on five weighted criteria. We did not conduct first-hand laboratory testing of competitor products; this is an editorial comparison built from published product specifications, brand documentation and verified third-party Certificates of Analysis where available. Prices were checked on July 22, 2026.

Purity grade (40%). USP pharmaceutical grade sits at the top, followed by pharmaceutical, then lab, food and undisclosed grades. Methylene blue is sold in industrial and aquarium grades that should never be ingested, so a documented human-use grade is the single most important factor. A bare “99.9% pure” label with nothing behind it does not count.

Third-party testing and COA (20%). A published batch Certificate of Analysis is the difference between a purity claim and a purity fact. Products with a verifiable COA scored highest; products with an unverified label claim scored lower regardless of the number printed on the bag. Our guide to what 99% USP purity actually means explains why the paperwork matters more than the marketing.

Price per dose (20%). We normalized cost to price per labeled serving, and to a 5 mg equivalent where the format allowed. Gummies frequently cost more per milligram than capsules or liquid once you strip out the sugar.

Customer reviews and reputation (10%). Marketplace visibility and review depth matter, but we weighted them lightly because review counts are easy to inflate and say nothing about grade.

Format and convenience (10%). Gummies win on taste and ease; capsules win on precision and a clean label; liquid wins on cost and fine dose control; powder is a separate category we cover in our methylene blue powder guide.

Frequently asked questions about methylene blue gummies

Do the methylene blue gummies really work?

Gummies deliver the same compound as capsules or drops, so the active ingredient works the same way — studies suggest low-dose methylene blue supports mitochondrial electron transport. In the leuco-form NooBlue gummy, the active arrives already reduced and electron-loaded, entering the same reversible redox cycle. The practical caveats apply to unverified products: marketplace gummy manufacturing holds tolerances loosely, and heat exposure degrades quality faster. A gummy from a brand with a batch COA works; an unverified marketplace gummy is a coin flip.

Who shouldn’t take methylene blue gummies?

The same exclusions as every methylene blue format: anyone taking SSRIs, SNRIs, or other serotonergic medications (research in the British Journal of Pharmacology identified methylene blue as a potent MAO-A inhibitor, and the combination has been linked to serotonin toxicity), people with G6PD deficiency, and anyone pregnant or breastfeeding. The gummy format adds one more group: households with children — a candy-like format deserves extra storage caution.

What is the best form of methylene blue?

The best form depends on what you value. For the easiest daily ritual with no staining, the leuco-form NooBlue Methylene Blue Gummies are the best format — a precise 10 mg with vitamin C, zero sugar, and no blue mouth. For dose accuracy at the lowest starting dose, the NooBlue capsules deliver an exact 5 mg of 99%+ USP grade every time. For the lowest cost per milligram and the finest dose control, a 1% liquid solution wins.

What are the best methylene blue gummies to buy in 2026?

The best methylene blue gummies in 2026 are the NooBlue Methylene Blue Gummies — the only gummy that pairs USP-grade methylene blue and a published COA with the reduced leucomethylene blue form, so there is no blue-mouth staining and the active starts in its more lipid-soluble, electron-loaded state. The Holistic MD gummies are the runner-up: verified and sugar-free, but built on conventional oxidized methylene blue.

What not to mix with methylene blue?

The most important interaction to avoid is with serotonergic medications. Methylene blue should not be combined with SSRIs, SNRIs or other serotonergic drugs, as the combination can be dangerous. It can also interact with certain other medications. Always talk to a qualified healthcare professional about your specific medications before starting methylene blue in any form.

Can you take methylene blue if you have lupus?

If you have lupus or any autoimmune or chronic condition, do not start methylene blue without first consulting your own doctor. Methylene blue can interact with medications and is not appropriate for everyone, and people with certain conditions — including G6PD deficiency — should avoid it. This guide is educational and is not a substitute for individual medical advice.

Can I take methylene blue every day?

Many people take a low daily dose of methylene blue, typically in the 5 to 15 mg range, and low-dose research has generally used single or short-course dosing. Whether daily use is right for you depends on your health, medications and goals, so confirm an appropriate routine with a healthcare professional. Starting low and using a precise format like a capsule or measured liquid makes a consistent daily dose easier to manage than a gummy.

How many milligrams are in a methylene blue gummy?

Most methylene blue gummies contain 5 mg to 20 mg each. Beginner gummies are usually 5 mg, NooBlue’s leuco-form gummy delivers a precise 10 mg, Holistic MD offers 7 mg and 14 mg options, and marketplace gummies reach 20 mg. If you want to start below 10 mg, a 5 mg capsule is the cleaner titration rung than splitting a gummy.

Are methylene blue gummies as good as capsules?

It depends on the gummy. Candy-grade marketplace gummies bind a variable amount of dye into a sugar matrix that is harder to dose consistently — a capsule beats those on every metric except taste. A precisely dosed, zero-sugar, COA-verified gummy like NooBlue’s closes that gap, and its leuco form adds something capsules don’t offer: no-stain chewing and a reduced, more lipid-soluble starting state. Choose the capsule for 5 mg titration, the gummy for the easiest 10 mg daily routine.

Where can I buy quality methylene blue gummies?

Buy from a brand that publishes a batch Certificate of Analysis and states a USP pharmaceutical grade. NooBlue’s leuco-form gummies ship worldwide direct from nooblue.com with a published CTLA COA; Holistic MD is the strongest verified conventional gummy. Avoid unbranded marketplace gummies that show no manufacturer and no COA.

The verdict: which methylene blue product should you buy in 2026?

For most people, the smartest buy in 2026 is the NooBlue Methylene Blue Gummies: a precise 10 mg of USP-grade methylene blue shifted into the reduced leucomethylene blue form by 25 mg of co-formulated vitamin C — zero sugar, a published CTLA Certificate of Analysis, and none of the blue-mouth staining that defines every other gummy here. If you want to titrate from a lower 5 mg dose, the NooBlue Methylene Blue Capsules are the precision rung. And if raw value is your priority, the NooBlue 1% Solution is the cheapest verified-purity option at roughly $0.30 per 5 mg serving. Whatever you choose, insist on a published COA and a stated pharmaceutical grade, and start at a low dose.