NERVEsustainTM vs. METANX®

“METANX” is a registered trademark of Alfasigma USA, Incorporated. It is classified as a medical “food”, although it comes in a capsule. METANX® boasts that it is specially formulated to meet the nutritional needs of those suffering from diabetic nerve damage, however, the “active ingredients” described to address symptoms of nerve damage and improve blood flow to restore healthy nerves are L-methylfolate (the activated form of folate/vitamin B-9), vitamin B-6, and vitamin B-12. It’s expensive, requires a prescription, and contains titanium dioxide. Any of these may be reasons you are interested in METANX alternatives.

Due to the long list of other ingredients in METANX®, it also may not be suitable for people with allergies, nor is it appropriate for vegans. It contains milk and soy, along with artificial coloring, shellac, sweeteners, oils, and other substances [1]. 

In terms of non-prescription METANX alternatives, you may want to consider nutritional supplements from Metabolic Maintenance. You can supplement he nutrients found in METANX® individually. You may also have an interest in Metabolic Maintenance’s clean, vegan option for peripheral nerve support called NERVEsustainTM. The NERVEsustainTM formula includes the same active ingredients (L-methylfolate, B-6, and B-12), as well as other beneficial nutrients, now including alpha-lipoic acid (ALA).

NERVEsustainTM is free of allergens, preservatives, food coloring, and binders. Additionally, Metabolic Maintenance pacakges all of its capsules in amber glass bottles to avoid the plastic contaminants that plastic prescription bottles can contain. 

What are METANX® ingredients?

Silicified Microcrystalline Cellulose, Algae-S Powder [Schizochytrium Algal Oil (Vegetable Source), Glucose Syrup Solids, Mannitol, Sodium Caseinate (Milk), Soy Protein, High Oleic Sunflower Oil, 2% or less Sodium Ascorbate, Tricalcium Phosphate, Tetrasodium Diphosphate, Natural Flavors, Soy Lecithin, and Mixed Natural Tocopherols and Ascorbyl Palmitate (as antioxidants)], Pullulan, Pyridoxal 5’- Phosphate (Vitamin B-6), L-methylfolate Calcium (Vitamin B-9), Methylcobalamin (Vitamin B-12), Titanium Dioxide (color), Magnesium Stearate (Vegetable Source), Caramel (color), Riboflavin USP, Shellac, Propylene Glycol USP. Contains Milk and Soy [2].

What’s in NERVEsustainTM?

Metabolic Maintenance does not use binders, fillers, added excipients or any preservatives in their supplements. NERVEsustain contains only, Alpha Lipoic Acid (ALA), vitamin B-6 (as Pyridoxal 5’ Phosphate), Thiamine (Vitamin B-1; as Thiamine Mononitrate), Magnesium (as Magnesium Citrate), Riboflavin (Vitamin B-2; as Riboflavin 5’ Phosphate), Folate (Vitamin B-9; as L-Methylfolate, Calcium salt), Vitamin C (as Ascorbyl Palmitate), and Vitamin B-12 (as Methylcobalamin), provided in a vegetarian capsule. That’s it.

Which Nutrients Support Nerve Health?

Healthy nerves rely on adequate levels of certain B vitamins (B-6, folate/B-9, and B-12 in particular), but occasionally, a few roadblocks stand in the way of attaining those levels. Some commonly prescribed medications interfere with the absorption of certain vitamins or deplete levels of certain B vitamins [6].

We also know now that it is extremely common to inherit MTHFR genetic polymorphisms can affect the body’s ability to properly process folate (vitamin B-9). Activated folate, L-methylfolate, is the type of folate necessary to encourage healthy blood flow, in order to supply damaged nerves with the proper nutrients to stimulate repair [1].

New research shows that ALA can support nerve health from multiple angles. Alpha-lipoic acid is a naturally occurring antioxidant that can work throughout the body, in every tissue, including nerves, as it is both water and fat soluble. Antioxidants are responsible for preventing or repairing cellular damage. This may be one of several mechanisms by which ALA supports nerve comfort [3].

ALA may also promote insulin sensitivity, healthy blood sugar levels, and healthy weight management [3].

METANX does not contain ALA, but NERVEsustain does.

Is L-methylfolate the same thing as folic acid?

The word folate is a blanket term for different forms of vitamin B-9. While the synthetic form of folate, folic acid, has a long history of use in both in nutritional supplements and food fortification, there are several biochemical steps between the folic acid you eat, and the active form your cells can actually use. Not everybody can perform these steps smoothly, leaving folic acid unmetabolized and needs for folate unfulfilled.

L-Methylfolate is the bioactive form of folate, that the body can actually use (without undergoing all of the biochemical steps that folic acid needs to be useful). L-Methylfolate is a more expensive ingredient than folic acid, so you will notice that specialty supplements that contain it are likely to carry a higher price tag. If you are folate deficient or have trouble processing folic acid due to an MTHFR mutation, it is well worth the investment to start meeting your body’s metabolic needs.

What is an MTHFR gene mutation (polymorphism)?

MTHFR is a gene that provides instructions to make an enzyme called methylenetetrahydrofolate reductase. Methylenetetrahydrofolate reductase is a necessary factor for dietary folate, and folic acid, to be transformed into active L-methylfolate (5-MTHF). About half of the global population carry an inherited mutation in the MTHFR gene [4]. If you have inherited a genetic mutation, it is possible to be metabolically folate deficient, even when your diet is high in folic acid. 

Only a genetic test by your doctor can confirm whether or not you have a MTHFR mutation, but if you do, L-methylfolate supplementation could be the answer. L-Methylfolate bypasses the entire folic acid metabolism cycle and is more effective than folic acid for increasing circulating folate in those with and without an MTHFR mutation [5].

What does NERVEsustainTM contain that METANX® doesn’t?

In addition to the active B-vitamins contained in METANX®, NERVEsustainTM includes other powerhouse nutrients in optimal levels known to aid in processes related to nerve support.

Alpha-Lipoic Acid (ALA) is a naturally occurring compound in the mitochondria of our cells. It takes part in regenerating other antioxidants including glutathione and vitamins C and E and in cellular energy production. It is both fat and water soluble and as such can provide its antioxidant properties to a wide variety of tissues including nerves. Studies show it may support nerve comfort [3]. Alpha-lipoic acid also aids in healthy glucose metabolism, a primary metabolic function that is important to overall nerve health [3].

Riboflavin (also known as vitamin B-2) is involved in the healthy metabolism of other B vitamins, including folate and B-6. It is also a cofactor for the MTHFR enzyme, aiding in the remethylation of homocysteine to methionine, and helping to keep homocysteine levels under control.

Thiamine (vitamin B-1) excessive alcohol consumption can deplete thiamine. Alcohol use can create alcohol-induced neuropathy, which can worsen in response to the depleting effect of alcohol on body stores of thiamine [6].

Magnesium is an essential mineral involved in both the normal transmission of nerve signaling and the modulation of a normal insulin response. When glucose levels are high, the body requires more magnesium, which means those with diabetes are at a higher risk of deficiency [7].

Ascorbyl Palmitate is a fat-soluble form of vitamin C. Vitamin C is a powerful antioxidant for tissue protection and some studies have shown it has the potential to boost the bioavailability of L-methylfolate [8].

Is a Medical Food Different From a Supplement?

Though both are formulations of nutritional ingredients, medical foods and nutritional supplements are different in several ways. One is how they are marketed and distributed, as described below.

What is a Medical Food?

Medical foods are specially formulated and processed for the specific dietary management of a disease or condition. They are not drugs, and so are not subject to regulations that apply specifically to pharmaceuticals. They do need to go through a research process to show that the food is beneficial for the condition for which the medical food company is making claims.

This research process is expensive, which increases the cost of the final product. Though they dont always require a prescription, the FDA does dictate that you must take a medical food “under the supervision of a physician”. So, most often a prescription is necessary.

What is a Nutritional Supplement?

A dietary or nutritional supplement is a product intended for ingestion, taken to supplement the nutritional content of a person’s diet. 

Nutritional supplements cannot legally make claims that they can be used to treat conditions. However, clinical studies often provide evidence for a nutrient’s benefit for specific health needs. Nutrition experts and physicians use clinical data to formulate supplements. These supplements can support specific biochemical pathways that the vitamin or other nutritional factor is known to influence.

A prescription is not needed to purchase a nutritional supplement, however, Metabolic Maintenance always recommends you check with your physician before adding anything new to your health regimen.

Insurance and Costs?

One benefit of getting a product certified as a medical food, available through prescription, is that insurance will sometimes cover some or all of the cost. However, certain coverage plans do not cover METANX® at all. The average retail cost for METANX® is $105 for a 30-capsule prescription.

Insurance will not cover NERVEsustainTM nutritional supplements. In some cases, you may be able to purchase nutritional supplements with a health savings account. However, by avoiding the lengthy and expensive “medical food” certification process, we are able to offer the same active ingredients, of equal or superior quality (plus other nutritional benefits like ALA), at a much lower cost. Currently, a NERVEsustain 30-day/30-capsule supply is $52. 

Cost is one of the biggest barriers between consumers and a product that may benefit their health immensely. Metabolic Maintenance has made a commitment to making supplements available at a fair, competitive price, without compromising the integrity, quality, or purity of our products.

Where can I buy NERVEsustainTM?

Although we always recommend consulting a doctor before making a change to your diet or nutritional regimen, Metabolic Maintenance’s NERVEsustainTM is available through our website No prescription necessary.

Nutritional supplements can arrive on your doorstep with no copay, no waiting in line, and no trip to the pharmacy. A subscription option is also available so that you will never have to go without your supplements.

What are the processes that guarantee this is a high-quality product?

There has been legitimate concern in the nutritional industry about the quality of supplements available to consumers. Consumers hear stories of products that contain little to no beneficial substance, or are contaminated with allergens, or mislabeled.

It is true, the FDA does not regulate the nutritional industry as tightly as the pharmaceutical industry. Unfortunately, this has led to some consumer mistrust, or an overall dismissal of the potential benefit of nutritional supplements.

However, there are nutritional companies making high-quality products. Metabolic Maintenance follows current Good Manufacturing Practices as certified by the FDA. We source all of our nutrients from companies that are as rigorous in their standards as we are. We send our raw materials out to a lab for third-party testing to ensure they correct and free of contaminants. After we blend, we send the product out again for third-party testing, to make sure our label claims are accurate.


  1. METANX Website. Covington, LA: Alfasigma USA, Inc.; Copyright 2019.
  2. METANX Package Insert. Covington, LA: Alfasigma USA, Inc.; Revised Feb., 2017.
  3. Nguyen, Ngoc, and Jody K. Takemoto. “A case for alpha-lipoic acid as an alternative treatment for diabetic polyneuropathy.” Journal of Pharmacy & Pharmaceutical Sciences 21.1s (2018): 192s-199s.
  4. Kaiser Permanente. “Basic Information About the MTHFR Gene.” The Permanente Medical Group, Inc. Copyright 2015, last reviewed 2018.
  5. Greenberg, James A., et al. “Folic acid supplementation and pregnancy: more than just neural tube defect prevention.” Reviews in Obstetrics and Gynecology 4.2 (2011): 52.
  6. Hammond N, Wang Y, Dimachkie M, Barohn R. Nutritional neuropathies. Neurol Clin. 2013 May; 31(2):477-489.
  7. Barbagallo M, Dominguez L. Magnesium and type 2 diabetes. World J Diabetes. 2015 Aug 25; 6(10): 1152-1157.
  8. Verlinde PN, Oy I, Hendrickx ME, et al. L-ascorbic acid improves the serum folate response to an oral dose of [6S]-5-methyltetrahydrofolic acid in healthy men. Eur J Clin Nutr. 2008; 62 (10): 1224-1230.