The Best L-Methylfolate Supplements

L-methylfolate supplements differ more than you might think. Quality, purity and bioavailability can vary widely depending on the source and manufacturing process. It’s worth researching products that use premium ingredients from verified sources and are backed by science.

The best products use clinically studied forms of methylfolate, sourced from verified suppliers, and formulated to meet the body’s biological needs.

There are some excellent brands on the market that tick all of these boxes, and Methyl-Life® is one of them. We’ll explain why below.

L-methylfolate is the active form of folate. However, there are many forms of methylfolate, and each can vary according to its structure and processing.

Several features can define a methylfolate product as the “best”.

Purity matters. The purer a compound, the more stable and effective it is in the body. Even the size of the particles can influence how well active ingredients are absorbed.¹

The higher the level of purity, the more stable a methylfolate product is, and the longer it will remain potent and effective. A study of over 5,000 compounds found that initial purity was the single most important factor affecting stability.²

This suggests that the best methylfolates should be as pure as possible in order to maintain their potency.

The natural, biologically active form of methylfolate is the (6S,αS) diastereoisomer. This is often labeled as:

• (6S)-5-Methyltetrahydrofolic Acid, Calcium Salt (L-methylfolate) or
• (6S)-5-Methyltetrahydrofolic Acid, Glucosamine salt or Monosodium Salt (L‐5‐methyltetrahydrofolic acid)

In contrast, forms labeled as DL-5-MTHF, 6RS-5-MTHF or simply 5-Methyltetrahydrofolate often contain a mixture of active and inactive isomers. These may include up to 50% of the (6R) isomer, which the body cannot use.

For people with MTHFR gene mutations - who already struggle to convert folic acid into active folate - this distinction is especially important.

Cerebrofolate® has been demonstrated as the most potent and therapeutic source of L-methylfolate on the market. This high-potency L-methylfolate is chemically identical to Metafolin®, used in the medical food Deplin®. Both Cerebrofolate® and Metafolin® are crystalline (6S)-5-MTHF calcium salts (with a Type I molecular structure), which are renowned for quality and purity.

Cerebrofolate® is exclusively available from Methyl-Life®:

• L-methylfolate supplements available OTC can vary considerably in terms of their potency, stability and purity
• Cerebrofolate® has been tested as the most bioavailable and therapeutic source of L-methylfolate available without a prescription (generally used under guidance of a healthcare professional)
• Both Cerebrofolate® and Metafolin® have the highest free L-methylfolate levels, indicating greater efficacy

When compared to Metafolin® and Quatrefolic®, Cerebrofolate® was tested as the most pure, with a total of 80.7% potency, the highest percentage of pure “free L-methylfolate”.

Impurities are the contaminants or degradation by-products present in the raw ingredient, which may occur during the processing or storage. Per USP standards, the sum of all impurities may not exceed 2.5% for L-methylfolate. The total impurities measured for Cerebrofolate® were lowest in comparison at 1.5%.

Every product in the Methyl-Life® range has been developed according to scientific research and formulated by a team of medical experts. All ingredients are certified for purity and efficacy and sourced from reputable suppliers. Cerebrofolate® also maintained the highest free L-methylfolate levels (≈80% potency), aligning with its low-impurity profile.

Methyl-Life® products are manufactured in a cGMP-compliant and NSF-certified facility, which exceeds the FDA’s highest quality standards.

Above all, Methyl-Life® uses the ultra-pure, trademarked Cerebrofolate®, one of the world’s most potent active L-methylfolates. Cerebrofolate® has been clinically tested against other leading brands as the most pure and stable form of methylfolate available to consumers.

The Methyl-Life® range includes dosages of 2.5 mg, 5 mg, 7.5 mg (with active B12), 10 mg and 15 mg and 15 mg+ (with active B12). Customers love the convenience and taste of the chewable tablets.

Methylfolate 2.5 is an excellent entry-level product. It contains Cerebrofolate® in a low but highly bioavailable 2,500 mcg dose, which is suitable for those who are new to methylfolate supplementation. It may also be combined with other products from the Methyl-Life® range that contain supportive cofactors which increase methylation efficiency.

Methyl-Life® products are free from wheat, gluten, starch, soy, egg, dairy, GMOs, fish/shellfish, yeast, nuts, caffeine, artificial colorings/flavorings, preservatives, bisphenol-A (BPA) or phthalates.

MethylPro is a reputable brand specializing in methylated supplements. All products are made with active ingredients free from wheat (gluten), eggs, milk, soybeans, shellfish, fish, peanuts and tree nuts.

The MethylPro range includes a variety of L-methylfolate dosages (2.5 mg, 5 mg, 7.5 mg, 10 mg and 15 mg). It also includes B vitamin complexes and products combining methylfolate with other cofactors. It is important to note that earlier MethylPro product documentation indicated the use of branded (6S)-5-methyltetrahydrofolate sourced from Gnosis Bio. Certain 10 mg formulations were described as containing Quatrefolic®, the glucosamine salt form of 6S-5-MTHF from Gnosis By Lesaffre, while some 15 mg products were previously identified as using Extrafolate-S®, a calcium amorphous salt form of 6S-5-MTHF.

However, current MethylPro product listings describe the ingredient more generally as L-methylfolate without specifying the branded raw material.

Type of Methylfolate: Generic L-5-Methylfolate, calcium salt and previously Quatrefolic® (6S)-5-Methyltetrahydrofolate (5-MTHF), Glucosamine Salt.

Now Foods is a low-cost supplement brand with over 1400 products. It caters to a broad range of health conditions rather than focusing solely on methylation-related health.

Now Foods methylfolate products are made with Quatrefolic® (6S)-5-Methyltetrahydrofolate (5-MTHF), Glucosamine Salt. As mentioned earlier, the crystalline calcium salt form of L-5-methyltetrahydrofolate (Cerebrofolate®)  has better stability than 6S-5-methyltetrahydrofolate glucosamine salt. Keep in mind that glucosamine salt must be taken at a higher dose because this form is less potent than the calcium-based form.

Type of Methylfolate: Quatrefolic® (6S)-5-Methyltetrahydrofolate (5-MTHF), Glucosamine Salt.

Thorne is a well-established supplement brand with a wide selection of products. Thorne uses third-party certified manufacturing facilities and claims that many of their supplements have been used in clinical trials, although their website doesn’t specify which publications or studies.

All Thorne products are free of gluten and artificial fillers, dyes and additives. Thorne products are more expensive than most other brands.

Thorne 5-MTHF 1 mg is formulated with Quatrefolic®, a crystalline glucosamine salt form of L-5-methyltetrahydrofolate manufactured by Gnosis S.p.A. 1 mg of L-5-MTHF provides approximately 1700 mcg DFE (dietary folate equivalent) according to U.S. labeling standards. Quatrefolic® is a stabilized, crystalline form and is not considered an amorphous salt.

Type of Methylfolate: L-5-Methyltetrahydrofolate, glucosamine salt.

Life Extension is another long-running US brand with a vast range of supplements. Their products are well-reviewed, and they can provide a Certificate of Analysis for every product.

Life Extension’s High Potency Optimized Folate contains (6S)-5-Methyltetrahydrofolate, calcium salt 8500 mcg of DFE (dietary folate equivalents). Their folate range includes Homocysteine Resist, which combines vitamins B2, B6, B12 and folate as L-5-MTHF and BioActive Folate & Vitamin B12.

Type of Methylfolate: (6S)-5-Methyltetrahydrofolate, crystalline form of calcium  (Extrafolate-S Crystal®)

Doctor's Best is a low-cost nutritional supplement company founded by a group of physicians. Its range includes over 200 products manufactured in cGMP-certified facilities. As with Now Foods, Doctor’s Best caters to a wide range of health conditions rather than methylfolate alone.

Doctor’s Best Fully Active Folate 400 and Folate 800 both contain Quatrefolic®. Doctor's Best Fully Active B Complex is also made with Quatrefolic®.

Type of Methylfolate: (6S)-5-methyltetrahydrofolate (5-MTHF), Glucosamine Salt