ConsumerLab Tests Identify Best Glycine Supplements

White Plains, NY, April 24, 2025 —  Glycine supplements are promoted to improve sleep and mood, reduce symptoms of overactive bladder and chronic prostatitis, and for other benefits, but do they really work, and if so, which glycine products on the market are best?

To identify the best products, ConsumerLab recently purchased and tested 10 popular glycine powders and capsules, checking if they contained their expected amounts of glycine. Products were also tested for heavy metals arsenic, cadmium, lead, and mercury, and powders were evaluated for mixability and taste.

The tests showed that the price of a glycine supplement was not an indicator of quality and the cost to obtain a 3-gram (3,000-mg) dose of glycine from the tested products ranged from 9 cents to more than $1.00. Furthermore, all of the glycine supplements contained the same, free form of glycine, providing no reason to pay more for glycine from one product than another.

The least expensive way to get glycine was generally from powders, particularly if taking large doses. Unlike some supplement powders, glycine naturally has a mildly sweet taste and mixes easily with water, although finely powdered glycine mixed more completely than granulated powders.

Among products that passed all tests and were Approved, ConsumerLab selected a Top Pick glycine powder and a Top Pick glycine capsule, representing high quality and exceptional value relative to other products reviewed.

Access the Full Report:

ConsumerLab’s full Glycine Supplements Review can now be accessed online by ConsumerLab.com members – who now number over 100,000.

The Glycine Supplements Review includes test results and comparisons for 10 glycine supplements selected for testing by ConsumerLab: BulkSupplements.com Glycine powder, Designs for Health Glycine Powder, Double Wood Supplements Glycine 1,000 mg, Life Extension Glycine 1,000 mg, NOW Glycine powder, NOW Glycine 1,000 mg, Nutricost Glycine – Unflavored powder, Pure Encapsulations Glycine capsules, Swanson Glycine Powder, and Thorne Glycine capsules.

As discussed in the Review, glycine is not considered an essential amino acid because the body can produce glycine. However, there may be times when the body may not produce glycine to meet metabolic demands. Glycine also acts as a neurotransmitter that's involved in controlling motor and sensory functions like movement, hearing, and vision. The Review also explains the best way to take and store glycine powders and capsules, and safety and side effects with glycine supplements.

A video that explains ConsumerLab’s findings and provides expert tips for selecting the best bone broth is freely available.

Founded in 1999, ConsumerLab.com is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. It has reviewed over 7,000 products and has published Product Reviews covering nearly every popular category of dietary supplements and health foods.

Membership to ConsumerLab.com is available online and provides immediate access to continually updated reviews of nearly every popular type of dietary supplement and health food, answers to reader questions, and product recalls and warnings. ConsumerLab also provides independent product testing through its voluntary Quality Certification Program. The company is privately held and based in New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products.

Glycine Supplements: What We Found After Testing 10 Popular Brands