dl-Phenylalanine and Pain Relief

Author: J. Clifford Richardson, M.D.

Phenylalanine is a readily available nutritional amino acid that may be obtained from various sources including vitamin and health food stores. This article discusses its use to block pain that may not be relieved by commercially offered medications.

Phenylalanine normally comes as a powder which may be enclosed for ease of use in a capsule. Like some other amino acids phenylalamine comes in two forms designated “D” and “L” ( for right and left). The difference between the forms is like the difference between your hands. They are identical, but are opposite, mirror images of each other. The left-handed form is known as L-phenylalanine (LPA). This is the form in which phenylalanine is normally found in foods. The right-handed form is known as D-phenylalanine (DPA). DPA is the form that protects endorphins in our bodies and helps us to fight pain and depression (Beckman et al. 1977; Cheng et al. 1979). A mixture of the two forms, which has been used to fight pain since 1978, is known as DL-phenylalanine (DLPA).

Phenylalanine protects our endorphins. It has helped many people overcome pain, as well as the depression that often accompanies chronic pain. In the original study of the effects of phenylalanine on pain, three of 10 patients reported significant relief. Phenylalanine has also been proven to be effective against painful inflammation. According to Russell et al. (2000), phenylalanine may work for up-regulating what is called the “endogenous analgesia system” (EAS), a neural pathway that occurs in a part of the spinal column. When stimulated by chronic pain or therapeutic measures such as opiates or acupuncture, the EAS suppresses activation of pain-receptive nerves in the spinal column and thereby alleviates pain (Russell et al.2000).

Phenylalanine is not a drug, and it does not work directly against pain. Instead, it acts as an endorphin shield, battling pain indirectly by helping the body’s built-in pain control system grow more powerful.

Phenylalanine was first tested against pain in a 1978 study at the Chicago Medical School. Researchers began by timing how long laboratory mice would remain on a hot plate before jumping off. Then they injected hundreds of mice with phenylalanine and again watched to see how long the mice would remain on the heated surface before scurrying off.

The amino acid blocked pain in 70% of the mice, allowing them to stay on the hot service longer. The pain blocking action actually grew stronger with time. Standard medicines tend to become less effective over time as the body grows accustomed to them, but phenylalanine was actually more effective on the ninth day than it was on the first. Plus, there was more good news. Phenylalanine worked with other medicines, making them stronger, and did all this without any apparent side effects.

Excited by these surprisingly positive results, the Chicago scientists tested phenylalanine on humans. The results were astounding. All 10 patients studied who had been suffering from long-standing chronic pain (people who had not been helped by modern medicine) found pain relief from this simple amino acid (Ehrenpreis et al. 1978). Phenylalanine relieved chronic pain that had not been helped by conventional methods. There were no harmful side effects, and no one became addicted (as can be the case with powerful pain medicines). Also, no one developed a tolerance to phenylalanine, requiring larger and larger doses to get the same effect, as is often the case with conventional pain drugs.

Additional research supported these early promising results. In one landmark study, 43 patients suffering from various types of severe pain were giving 250 mg of phenylalanine 4 times a day. Some of the patients reported marked relief within 1 week. But by the end of the fourth week, 75% of the patients reported that their pain had been relieved (Balagot et al. 1993).

In Great Britain, a double-blind controlled study was undertaken to determine whether the amino acid really worked or whether the pain relief reported in other studies was caused by the so-called placebo effect. It is well-known that the power of belief can act as a medicine. Thus, when patients are given pills that contain no medicine but are told that the pills contain powerful drugs, many patients will get better. The participants in the study were adults suffering from long-standing, intractable pain of various causes that had not been cured by conventional drugs or physical therapy. Despite the fact that lower doses of the substance were given and a 50% reduction in pain was required to qualify as improvement, more than 30% of the participants experienced significant relief. Phenylalanine outperformed the placebo, showing that it is, indeed, and powerful medicine (Budd1983).