DL-phenylalanine is used as a medical treatment, rather than the two separate forms of phenylalanine, because both are found to be effective under different circumstances and to treat different conditions, so they are combines to maximize the effectiveness of the amino acid.

Phenylalanine and its forms

Phenylalanine is an amino acid. Amino acids are sometimes referred to as ‘the building blocks of life’.

Phenylalanine belongs to a particular group of amino acids known as essential amino acids, which basically means that they are needed by the body to carry our its everyday functions, but that the body itself cannot manufacture them, so they must be obtained by dietary means.

The most common form of phenylalanine in nature is L-phenylalanine.

D-phenylalanine is a synthetic form of phenylalanine that mirrors its natural cousin, and DL-phenylalanine therefore is a combination of these two amino acids.

Phenylalanine is converted into tyrosine in the human body.

Tyrosine is needed for the manufacture of certain proteins, hormones and neurotransmitters, therefore phenylalanine deficiency can present with a variety of symptoms ranging from lethargy and tiredness to confusion and mental impairment.

Sometimes children are born without the ability to manufacture an enzyme crucial to the metabolizing of phenylalanine, a condition known as PKU.

Left untreated, PKU can cause serious and irreversible mental retardation.

Usefulness of DL-phenylalanine

DL-phenylalanine has been shown in certain studies to be able to reduce the chronic pain caused by some conditions, and scientists believe that this may occur due to the phenylalanine stimulating the production of neurotransmitters such as serotonin, which act to depress the nervous system and hence dull the pain.

Similar studies indicated that the painkilling effects of phenylalanine worked in synergy with other painkilling medication to produce an effect that was greater than when either was taken separately.

Another study indicates that phenylalanine may have a beneficial effect for those with certain physical and psychological disabilities, including but not limited to speech problems and Parkinson’s disease, as well as some forms of depression.

Further studies into this area of possible phenylalanine use are ongoing.

Vitiligo is a medical condition that causes depigmentation of the skin, presenting as irregularly shaped white patches.

There is evidence to suggest that phenylalanine applied both topically and orally, and combined with controlled doses of UV radiation, may help to re-pigment areas of damaged skin with minimal risk of side-effects.

Again, research into this particular aspect of phenylalanine is currently underway.

Necessity in medical science

The role of phenylalanine in the production of neurotransmitters, including serotonin, dopamine and norepinephrine, leads some doctors to believe that this essential amino acid may prove effective in the treatment of depression.

Supporting these claims is the anecdotal evidence of some sufferers of depression that phenylalanine supplementation did indeed help to relieve their symptoms in a manner which prescription drugs had thus far been unable to do.

Several controlled studies have also found much evidence in support of the use of phenylalanine as a natural antidepressant, with many subjects reporting reduced symptoms of anxiety and depression following a course of the amino acid.

Other studies have shown that phenylalanine can be an effective analgesic, with patients reporting a decrease in their symptoms of pain following a course of DL phenylalanine.

Again, this painkilling property can possibly be enhanced by combining phenylalanine with one or more prescription painkillers, upon which it appears to have an enhancing effect.

The natural form of phenylalanine, L-phenylalanine, can be gleaned naturally from food sources such as meat, fish, dairy products, nuts, seeds and soy.

The popular sweetening product aspartame also contains a substantial amount of phenylalanine.

How to take it?

D-phenylalanine is not found in any foodstuffs, as it is always manufactured under laboratory conditions.

  • Availability

DL phenylalanine is available as a supplement in a variety of forms, most commonly capsules and powder, but also as a topical cream for the treatment of pain and skin conditions such as vitiligo.

  • Doses

The recommended dose of phenylalanine varies from person to person and condition to condition, so you should always read the label and preferably consult a medical professional before taking any medication or dietary supplements.

It is believed that phenyalanine can have optimal beneficial effects when taken around twenty minutes before mealtimes, to increase the absorption rate of the amino acid.

  • Words of caution

Pregnant women should not take phenyalanine without seeking the advice of their doctor first, and this amino acid may cause side-effects for some people, including psychological effects such as anxiety and depression.

High doses of phenylalanine can cause damage to the nervous system, so moderation is strongly advised.

Phenylalanine overdose can present with symptoms of nausea and headaches.