Glycine

Other Name(s):

Acide Aminoacétique, Acide Amino-Acétique, Aminoacetic Acid, Athenon, Free Base Glycine, G Salt, Glicina, Glycine de Base Libre, Glycocoll, Glycosthene, Iconyl, L-Glycine, Monazol.

Overview

Glycine is an amino acid, a building block for protein. It is not considered an “essential amino acid” because the body can make it from other chemicals. A typical diet contains about 2 grams of glycine daily. The primary sources are protein-rich foods including meat, fish, dairy, and legumes.

Glycine is used for treating schizophrenia, stroke, benign prostatic hyperplasia (BPH), and some rare inherited metabolic disorders. It is also used to protect kidneys from the harmful side effects of certain drugs used after organ transplantation as well as the liver from harmful effects of alcohol. Other uses include cancer prevention and memory enhancement.

Some people apply glycine directly to the skin to treat leg ulcers and heal other wounds.

How does it work?

The body uses glycine to make proteins. Glycine is also involved in the transmission of chemical signals in the brain, so there is interest in trying it for schizophrenia and improving memory. Some researchers think glycine may have a role in cancer prevention because it seems to interfere with the blood supply needed by certain tumors.

QUESTION

Schizophrenia is the most disabling mental illness. See Answer

Uses & Effectiveness

Possibly Effective for...

  • Treating schizophrenia, when used with other conventional medicines.
  • Treating leg ulcers, when applied as a cream that also contains other amino acids.
  • Treating the most common form of stroke (ischemic stroke). Putting glycine under the tongue may help to limit brain damage caused by an ischemic stroke when started within 6 hours of having the stroke. An ischemic stoke is caused by the blockage of a blood vessel (usually by a clot) in the brain. Brain cells beyond the obstruction don't receive oxygen and begin to die, causing irreversible damage.

Insufficient Evidence to Rate Effectiveness for...

  • Memory enhancement.
  • Benign prostatic hypertrophy (BPH).
  • Liver protection.
  • Cancer prevention.
  • Other conditions.
More evidence is needed to rate the effectiveness of glycine for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Side Effects

Glycine seems to be safe for most people when taken by mouth or applied to the skin. Most people do not experience side effects, although there have been a few reports of nausea, vomiting, stomach upset, and drowsiness.

SLIDESHOW

Schizophrenia: Symptoms, Types, Causes, Treatment See Slideshow

Special Precautions & Warnings

Pregnancy and breast-feeding: Not enough is known about the use of glycine during pregnancy and breast-feeding. Stay on the safe side and avoid use.

Interactions


Clozapine (Clozaril)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Clozapine (Clozaril) is used to help treat schizophrenia. Taking glycine along with clozapine (Clozaril) might decrease the effectiveness of clozapine (Clozaril). It is not clear why this interaction occurs yet. Do not take glycine if you are taking clozapine (Clozaril).

Dosing

The following doses have been studied in scientific research:

BY MOUTH:

  • For treating schizophrenia: Glycine has been used in doses ranging from 0.4 to 0.8 g/kg daily in divided doses. It is usually started at 4 g daily and increased by 4 g per day until the effective dose is reached.
UNDER THE TONGUE:
  • For protecting brain cells (neuroprotection) after onset on a stroke caused by a clot (ischemic stroke): 1 to 2 g per day started within 6 hours after stroke onset.
APPLIED TO THE SKIN:
  • For treating leg ulcers: A cream containing 10 mg of glycine, 2 mg of L-cysteine, and 1 mg of DL-threonine per gram of cream has been used. The cream was applied at each wound cleaning and dressing change once daily, every other day, or twice daily.

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

References

de Koning TJ, Duran M, Dorland L, et al. Beneficial effects of L-serine and glycine in the management of seizures in 3-phosphoglycerate dehydrogenase deficiency. Ann Neurol 1998;44:261-5.. View abstract.

Evins AE, Fitzgerald SM, Wine L, et al. Placebo-controlled trial of glycine added to clozapine in schizophrenia. Am J Psychiatry 2000;157:826-8.. View abstract.

File SE, Fluck E, Fernandes C. Beneficial effects of glycine (bioglycin) on memory and attention in young and middle-aged adults. J Clin Psychopharmacol 1999;19:506-12. . View abstract.

Fries MH, Rinaldo P, Schmidt-Sommerfeld E, et al. Isovaleric acidemia: response to a leucine load after three weeks of supplementation with glycine, L-carnitine, and combined glycine-carnitine therapy. J Pediatr 1996;129:449-52.. View abstract.

Gusev EI, Skvortsova VI, Dambinova SA, et al. Neuroprotective effects of glycine for therapy of acute ischaemic stroke. Cerebrovasc Dis 2000;10:49-60. View abstract.

Harvey SG, Gibson JR, Burke CA. L-cysteine, glycine and dl-threonine in the treatment of hypostatic leg ulceration: a placebo-controlled study. Pharmatherapeutica 1985;4:227-30.. View abstract.

Heresco-Levy U, Javitt DC, Ermilov M, et al. Double-blind, placebo-controlled, crossover trial of glycine adjuvant therapy for treatment-resistant schizophrenia. Br J Psychiatry 1996;169:610-7.. View abstract.

Heresco-Levy U, Javitt DC, Ermilov M, et al. Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia. Arch Gen Psychiatry 1999;56:29-36.. View abstract.

Javitt DC, Balla A, Sershen H, Lajtha A. A.E. Bennett Research Award. Reversal of phencyclidine-induced effects by glycine and glycine transport inhibitors. Biol Psychiatry 1999;45:668-79.. View abstract.

Javitt DC, Zylberman I, Zukin SR, et al. Amelioration of negative symptoms in schizophrenia by glycine. Am J Psychiatry 1994;151:1234-6.. View abstract.

Potkin SG, Jin Y, Bunney BG, Costa J, Gulasekaram B. Effect of clozapine and adjunctive high-dose glycine in treatment-resistant schizophrenia. Am J Psychiatry 1999;156:145-7.. View abstract.

Rose ML, Cattley RC, Dunn C, et al. Dietary glycine prevents the development of liver tumors caused by the peroxisome proliferator WY-14,643. Carcinogenesis 1999;20:2075-81.. View abstract.

Rose ML, Madren J, Bunzendahl H, Thurman RG. Dietary glycine inhibits the growth of B16 melanoma tumors in mice. Carcinogenesis 1999;20:793-8.. View abstract.

Thurman RG, Zhong Z, von Frankenberg M, et al. Prevention of cyclosporine-induced nephrotoxicity with dietary glycine. Transplantation 1997;63:1661-7.. View abstract.

Yin M, Ikejima K, Arteel GE, Seabra V, et al. Glycine accelerates recovery from alcohol-induced liver injury. J Pharmacol Exp Ther 1998;286:1014-9.. View abstract.

Zhong Z, Arteel GE, Connor HD, et al. Cyclosporin A increases hypoxia and free radical production in rat kidneys: prevention by dietary glycine. Am J Physiol 1998;275:F595-604.. View abstract.