Partial
“A 5,000 mcg megadose is more effective”
Passive diffusion absorbs only about 1% of an oral dose, so a larger dose does raise the absolute amount absorbed — but 1,000 mcg already corrects deficiency and the excess is excreted (Stabler 2013).
Reviewed
Verified by SAC team
+20
XP on completion
Best High-Dose Sublingual
NOW Foods
NOW Supplements Methyl B-12 (Methylcobalamin) 5,000 mcg - 120 Lozenges Review
If you specifically want a high-dose sublingual, NOW's A-rated 5,000 mcg lozenge is the best-executed version of that idea. NOW earns trust with an in-house, UL-audited GMP and testing program that consumer watchdogs rate highly, and the per-serving cost is strong for a 5,000 mcg lozenge. The catch is the concept itself: 5,000 mcg vastly exceeds what your body can use, so most of it is excreted, and the 'sublingual beats swallowing' claim is thin.
Check on AmazonAffiliate link — Super Achiever Club earns a small commission at no extra cost to you.
Read the complete Vitamin B12 guide →How we built the SAC Product Score™ — 8/10
Form & Bioavailability20%8.5/10
Active methylcobalamin in a sublingual lozenge. The methyl form is fine; the sublingual angle is the weak part — evidence that it out-absorbs a swallowed dose is thin.
Dose vs Clinical Range20%6.3/10
5,000 mcg is a megadose far above the oral repletion range. Absorption is saturable, so the body uses only a small fraction and excretes the rest — the main reason this pick sits lower.
Third-Party Testing & Purity25%8.3/10
NOW runs an in-house, UL-audited GMP and testing program that consumer watchdogs rate highly (A-rated). It's a strong operation, though it's not an independent USP or NSF product seal.
Value Per Serving15%8.5/10
At ~$0.15/serving it's strong value for a 5,000 mcg sublingual, single-active formula — you get a lot of B12 per dollar, even if you don't need it all.
GI Tolerance & Format Suitability20%8.4/10
A chew-or-dissolve lozenge that's easy for pill-averse users and generally well tolerated, with no swallowing required.
The product at a glance
- Form
- Methylcobalamin (sublingual lozenge)
- Dose
- 5,000 mcg per lozenge
- Count
- 120 lozenges / 120 servings
- Testing
- UL-audited GMP; A-rated by watchdogs (no USP/NSF seal)
- Delivery
- Chew or dissolve in mouth
- Cost per serving
- ~$0.15
Marketing claims vs. reality
Not verified
“Sublingual absorbs better than swallowing”
Head-to-head evidence that sublingual outperforms swallowed B12 is thin; oral repletion doses already normalize status (Wang Cochrane 2018).
Verified
“In-house, UL-audited GMP and testing”
NOW's testing program is UL-audited and rated highly (A-rated) by consumer watchdogs, though it's not an independent USP or NSF product seal.
Not verified
“Boosts energy in healthy adults”
B12 only relieves fatigue when it corrects a real deficiency; a megadose in replete people does not add energy (Tardy 2020).
What our test actually found
01The brand is the strength
NOW's in-house, UL-audited testing is genuinely reassuring and watchdog-rated. If you want a high-dose sublingual, this is the best-run one.
02The dose is the weakness
5,000 mcg is far more than your body can use. Most of it is excreted, so the megadose is a marketing number, not a repletion advantage.
03Sublingual is a thin promise
The 'dissolves under the tongue so it absorbs better' pitch isn't well supported. It's a fine format, not a superior one.
04Strong value for what it is
At about fifteen cents a lozenge, it's good value in the sublingual category — just remember you're paying for B12 you'll mostly excrete.
Pros & cons, no sugar-coating
Pros
- A-rated, UL-audited in-house GMP and testing program
- Strong cost per serving for a 5,000 mcg sublingual
- 120-count, single-active formula
- Reputable, watchdog-favored brand
Cons
- 5,000 mcg is a megadose — most of it is simply excreted, not used
- The 'sublingual absorbs better than swallowing' claim is weakly supported
- No USP or NSF seal
Best execution of a concept you may not need
NOW earns trust with an in-house, UL-audited GMP program that consumer watchdogs rate highly, and the per-serving cost is strong for a 5,000 mcg sublingual. But the dose is the catch: 5,000 mcg vastly exceeds what your body can use, so most of it is excreted, and the 'sublingual beats swallowing' claim is thin. It's a great execution of a concept you probably don't need.
Check NOW Foods on AmazonIf this doesn’t fit — try these
Jarrow Methyl B-12 5000 mcg Cherry
7.3/10A cheaper, flavored take on the same high-dose sublingual idea.
See it on the list →THORNE Vitamin B12 (Methylcobalamin)
9.2/10A sensibly-dosed 1,000 mcg capsule with elite testing.
See it on the list →Garden of Life mykind B12 Spray
8.3/10A no-pills format at the most physiological dose.
See it on the list →Sources & further reading
- Stabler SP. Vitamin B12 Deficiency. N Engl J Med. 2013;368(2):149-160.Stabler SP · 2013 · New England Journal of Medicine · PMID 23301732
Vitamin B12 Deficiency
Oral cobalamin absorption is saturable; around 1,000 mcg corrects deficiency and larger doses offer little added repletion benefit.
- Wang H, et al. Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. Cochrane Database Syst Rev. 2018;3:CD004655.Wang H, Li L, Qin LL, et al. · 2018 · Cochrane Database of Systematic Reviews · PMID 29543316
Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency
Standard oral repletion normalizes B12; no clear superiority is demonstrated for sublingual over swallowed delivery.
- Tardy AL, et al. Vitamins and Minerals for Energy, Fatigue and Cognition. Nutrients. 2020;12(1):228.Tardy AL, Pouteau E, Marquez D, et al. · 2020 · Nutrients · PMID 31963141
Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence
Correcting a B12 deficiency reduces fatigue, but a megadose in already-replete people does not increase energy.