Which threonine supplements are best?

Threonine is an essential amino acid that helps build connective tissues such as elastin and collagen. It also helps regulate muscle growth and can balance mood and digestion. Essential amino acids are not created by your body — they rely on diet to become part of your system. If you’re not getting enough threonine through diet alone, a supplement is a great aid to ensure your body stays healthy and functioning.

If you’re looking for the best of the best, Life Extension Magnesium L-Threonate has 2,000 milligrams of L-threonine per capsule and is made with raw ingredients for purity and quality.

What to know before you buy a threonine supplement

What threonine is

Threonine, or L-threonine, is both an essential amino acid and a regulated protein in your body. Essential amino acids are not synthesized by the body, says Examine. It aids in muscle growth and helps strengthen cognitive functions such as memory. If you are lacking in threonine, you may suffer from mood swings, irritability, confusion and digestive issues. High-protein foods are a great source of threonine.

How threonine works

Once ingested, threonine changes to a chemical called glycine. Glycine works in the nervous system to regulate muscle growth, reduce muscle spasms and boost cognitive functions. 

Threonine’s benefits

Threonine supports digestive health, muscle growth and strength, prevents fatty liver and may alleviate anxiety and depression. 

  • It creates a mucus gel layer in your digestive system that fights off harmful digestive enzymes.
  • It produces collagen and elastin proteins that build the connective tissue between muscles and bones. More threonine means stronger connective tissue, increasing your overall muscle and bone strength. It may also improve wound healing as connective tissue is strengthened by added collagen support. Also, the glycine produced by threonine treats spasticity and some people with ALS, or Lou Gehrig’s disease, turn to threonine to reduce spasms and contracting muscles.
  • It prevents fat buildup in the liver by regulating fat metabolism. The acids in threonine aid in lipotropic function, and a deficiency in threonine may result in liver failure.
  • The glycine produced by threonine supports cognitive health and function. It may also calm nerves and promote a good night’s rest. Glycine, in low levels, may result in depression, so taking threonine supplements can aid in alleviating anxiety and depression.

What to look for in a quality threonine supplement


A typical dose of threonine is anywhere from 150 to 500 milligrams daily. You may take them once daily or multiple times a day before meals. The dose and timing depends on your needs. Consult your physician to know what is right for you.


Threonine supplements come in powder or capsule form. If you have trouble swallowing or ingesting pills, a powder is a great option. However, powder needs to be mixed with liquid and may have a taste some consumers dislike.

Vegetarian capsules

Some capsules are made with gelatin. Gelatin is derived from animals and is not vegetarian or vegan-friendly. Check the supplement ingredient list to know if it is gelatin-free. If it’s not listed on the ingredients, go to the brand’s website for more information.

Side effects

Threonine supplements are generally considered safe. Some people may experience mild side effects such as nausea, upset stomach, skin rash or headaches. It is not advised for women who are pregnant or breastfeeding to take threonine supplements. Also, people taking certain medications associated with Alzheimer’s disease should avoid threonine supplements as there may be negative drug interactions. Consult your doctor if you are concerned about potential side effects.

How much you can expect to spend on a threonine supplement

Threonine supplements range in price from $11 to over $20 depending on quality, form and quantity.

Threonine supplement FAQ

What are good sources of threonine in food?

A. High-protein foods are great sources of threonine. Foods such as lean beef, pork, lamb, cheese, cashews, almonds, pistachios, carrots, bananas, eggs and lentils are high in threonine. If you are vegan or vegetarian, beans, seeds and peas will help maintain good threonine levels in your body.

What is the difference between L-threonine and L-theanine?

A. L-threonine improves cognitive function and muscle health while L-theanine promotes relaxation and provides calming effects.

Does threonine make you sleepy?

A. Threonine promotes sleep and rest, calming the nervous system. It can be used to facilitate sleep, but it does not make you drowsy.

What are the best threonine supplements to buy?

Top threonine supplement

Life Extension Magnesium L-Threonate

Life Extension Magnesium L-Threonate

What you need to know: This capsule has 2,000 milligrams of L-threonine and promotes memory, focus and boosts overall brain performance.

What you’ll love: It’s free of gluten and genetically modified organisms, and made with raw ingredients for purity and quality.

What you should consider: Capsules may be difficult to swallow, especially if you have trouble ingesting pills.

Where to buy: Sold by Amazon

Top threonine supplement for the money

BulkSupplements.com L-Threonine Powder

BulkSupplements.com L-Threonine Powder

What you need to know: This mood-boosting powder contains 2,000 milligrams of threonine per serving and helps maintain liver, joint and brain health.

What you’ll love: It’s cost-effective and unflavored. Add it to your favorite smoothie or shake for an extra immune boost.

What you should consider: This package contains only 3.5 ounces, which is less than other threonine supplements.

Where to buy: Sold by Amazon

Worth checking out

Pure Organic Ingredients L-Threonine Capsules

Pure Organic Ingredients L-Threonine Capsules

What you need to know: This 100-day supply will help with muscle tightness and is made in the USA.

What you’ll love: It’s free of additives and fillers and contains 525 milligrams of threonine per serving.

What you should consider: These capsules are made with gelatin and are not vegetarian or vegan-friendly.

Where to buy: Sold by Amazon

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Lilliana Winkworth writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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