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Amino Acids and Diet in Chronic Pain Management

This first installment of a multi-part series on amino acids and diet outlines their critical importance in pain practice.
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Table 2. Primary Pain-modulating Neurotransmitters
Neurotransmitter Amino Acid Source Pain Type
Endorphin: Potent group of endogenous opioids·
  • d-phenylalanine
  • a 20 amino acid chain
Very broad analgesic effects
Serotonin: Inhibitory (soothing), sleep-promoting
  • 5-hydroxytrytophen
  • I-tryptophan
Fibromyalgia, migraine, general analgesia

Table 3. Foods That Contain Protein

Over 50%
Cottage Cheese

Between 20 and 30%
Green vegetables

Table 4. Sample calorie and protein contents of various hospital diets8
Type of Diet Kcal/day Grams protein/day
Regular 2600 100
Clear liquid 1300 27
Soft 2300 90
Full liquid 1600 53
Pureed 1500 90

Table 5. Recommended Dosing with Amino Acid Supplements.9
Amino Acid Dose
To raise endorphin levels:
• D-phenylalanine (DPA)

500mg Tid
• Plus a complete amino acid blend 700mg Tid
To raise serotonin levels:
• 5-HTP

50mg (1-3) mid afternoon and bedtime
• or, l-tryptophan 500mg (1-3) mid afternoon and bedtime
To raise GABA levels:

250-500mg, midmorning, mid-afternoon,and bedtime
• or, l-glutamine 500mg (2-3) midmorning, mid-afternoon, and bedtime

Individual amino acids are commercially available as tablets, capsules, powders, or administered by I.V. pain practitioners will want to identify the single amino acids that will best benefit particular patients. All amino acids are classified by the U.S. Food and Drug Administration as dietary supplements, so they are widely available at reasonable prices in health food stores, pharmacies, catalogs, and on the internet.

Amino acid blends are widely sold in drinks or powders, and advertised or labeled for “energy,” “brain power,” or “body building.” The dosages in most of these products, however, are usually too low to be of much benefit to chronic pain patients. We therefore recommend that practitioners use concentrates of the specific amino acids indicated in Table 2, along with a high quality, free-form amino acid blend containing all 20 amino acids.

The common mistake when recommending amino acids to patients is rooted in the misunderstanding that amino acids, unlike the usual prescription tablet or capsule, is highly soluble in food. In fact, the protein content of a meal will compete with supplemental amino acids for entry into the brain. It is best, therefore, to take amino acids between or before meals. The cardinal rule in the use of amino acids: take on an empty stomach with cold fluids. Recommended dosing with amino acid supplements are summarized in Table 5.

Where To Start?

We recommend that you start by taking a one minute dietary history from chronic pain patients to determine how much protein is consumed on a daily basis. Our guess is that you will be as shocked as we have been to see how little protein is consumed by chronic pain patients. Next, give them a copy of the major protein foods (Table 3), and inform them of the necessity of increasing protein. While the diabetologist may champion the low sugar diet and the cardiologist the low fat diet, pain practitioners must preach the “high protein” diet.


Little attention has been paid to diet and amino acid needs in our relatively new pain treatment field. The key to nutritional counseling in chronic pain patients is to appreciate the critical contribution of dietary protein and amino acid supplementation.

Last updated on: January 6, 2012
First published on: April 1, 2009