Flip and mix molecules of phenylalanine, and you’ll get DPLA: an amino acid mixture with surprising features. It may help you overcome depression, chronic pain, and the inability to focus. Read on to see if DLPA is for you and how to take it.

What is DLPA?


DLPA (DL-phenylalanine) is a nutritional supplement with 2 different forms of phenylalanine in equal amounts: D- and L-phenylalanine. As you can see in the image above, they are “mirror images” of the same amino acid oriented differently in space [1].

L-phenylalanine is the active form in the human body; it builds proteins, neurotransmitters, and other crucial molecules. It’s an essential amino acid, which means we need to get it from foods such as eggs, meat, soy, nuts, and dairy [2, 3].

D-phenylalanine is the synthetic form made in the lab. Although our bodies can’t use it as a building block, it produces specific health effects [4, 5].

People take DLPA to boost energy, manage pain, balance mood, and more. Let’s see what the science and clinical evidence say about this supplement…



  • May help with depression
  • May reduce pain
  • May boost mental clarity


  • Not well studied in humans
  • Dangerous for people with phenylketonuria

How Does DLPA Work?

L-phenylalanine builds neurotransmitters such as dopamine and noradrenaline that control mood, mental health, heart rate, and other vital functions. As a supplement, it may help with [6, 7, 8, 9, 10]:

Your body converts about ⅓ of D-phenylalanine into the L-form, while the rest has unique effects. Supplementation with D-phenylalanine can increase your natural opioids, enkephalins, and soothes inflammation. It may help with [4, 11, 12, 13]:

In theory, DLPA should deliver the combined health benefits of both forms with fewer side effects, but there’s no substantial evidence to back this up.

DLPA Benefits

1) May Combat Depression

Your brain uses L-phenylalanine in DLPA to produce mood-boosting neurotransmitters such as dopamine and noradrenaline. Low brain levels of these chemicals often lurk behind the symptoms of depression [6, 14].

D-phenylalanine may also contribute by boosting natural opioids in the brain [15].

In a clinical trial on 40 depressed patients, DLPA (150-200 mg/day) had the same effect as an antidepressant, imipramine. However, the authors pointed to study design flaws that may have skewed the results [16].

DL-phenylalanine (75-200 mg/day for 20 days) wiped out the symptoms of depression in 12 out of 20 patients. It offered mild to moderate benefits in 4 more patients, while it failed to affect the remaining 4 [17].

Lower doses of the same supplement (50-100 mg daily for 15 days) restored normal mood in 17 out of 23 depressed patients who didn’t respond to standard treatment [18].

The above studies are over 40 years old and lack placebo controls. We should take their results with a grain of salt.

2) May Ease the Pain

Doctors are struggling to manage their patients’ chronic pain. The standard painkillers only work to an extent and carry serious long-term risks [19].

D-phenylalanine – the other half of DLPA – raises the levels of our internal opioids, which relieves pain without major adverse effects [20, 21].

Although clinical trials haven’t found the same for DLPA, some doctors have reported positive results in pain management with large doses (1,500-3,000 mg daily). DLPA’s antidepressant and painkiller effects are tightly linked [22].

Bottom line? We need more evidence before proclaiming DLPA a natural painkiller.

3) Attention Disorders

Low dopamine is one of the triggers of ADHD. By providing L-phenylalanine for dopamine production, DLPA may help with ADHD and other attention disorders [23].

In one older analysis, 44 children with ADHD had lower blood and urine phenylalanine levels than their healthy peers. But according to a more recent study, children with ADHD have normal phenylalanine levels [24, 25].

DLPA improved symptoms such as anger, restlessness, and poor concentration in 19 adults with ADHD. However, 3 months after the study finished, the beneficial effects disappeared [26].

D-phenylalanine had no beneficial effects on 19 hyperactive boys in another study [27].

Based on the available research, phenylalanine does not help with ADHD symptoms [28].

4) Weight Loss

L-phenylalanine may reduce food intake and boost fat burning. As a source of this amino acid, DLPA might help with weight loss, but no studies have confirmed this yet [9, 29].

5) Opiate Withdrawal

Opiate dependence is a growing medical concern while the opioid epidemic was declared a public health emergency in the US in 2017 [30, 31].

By increasing the levels of internal opioids, D-phenylalanine may improve mood and help people undergoing opiate withdrawal [20, 12].

DLPA is 50% D-phenylalanine so it might deliver the same benefits, but once again, there’s no evidence to back this up.

Side Effects & Safety

Clinical trials reported no significant DLPA side effects [18, 17, 16, 26].

L- and D-phenylalanine as single supplements are also safe and well-tolerated [10, 27].

L-phenylalanine may cause nausea in higher doses and interact with a drug for Parkinson’s disease, L-DOPA. The same might go for DLPA [32, 33].

Although DLPA is safe in general, there’s a massive exception to this rule!

People with a rare metabolic disorder – phenylketonuria (PKU) – are unable to process phenylalanine properly. The accumulation of this amino acid can cause brain damage and cognitive impairment in PKU patients [34, 35, 36].

These people follow a special low-protein diet to minimize the intake of phenylalanine. Obviously, they should steer clear of DLPA other phenylalanine supplements [37, 38].

Children and pregnant women should also avoid DLPA due to the lack of safety data.

DLPA Supplements

Most supplements contain pills with 500-1,000 mg of DLPA. Bulk powder with 375 mg per serving is also available.


The following DLPA dosage had beneficial effects in clinical trials:

  • Depression: 50-200 mg for 2-4 weeks [16, 17, 18]
  • Attention Deficit Disorder: increasing from 150 to 1,200 mg daily for 2 weeks [26]
  • Chronic pain: 1,500-3,000 mg daily (from clinical experience) [22]


Plenty of users have reported success with depression and mood disorders, although they mostly use DPLA in combination with other supplements such as fish oil, 5-HTP, and B vitamins.

Others take it to boost mental clarity and ease chronic pain, and they report mild improvements.

On the other hand, some users experienced no benefits from DLPA supplements. The most common side effects include:

  • Headache
  • Irritability
  • Nausea

Is DLPA Better Than L-Phenylalanine?

In theory, DLPA should deliver additional benefits compared with L- phenylalanine, but the evidence tells a different story.

DepressionWeight lossPainAddictionADHDVitiligo


In summary:

  • They both may help combat depression
  • L-phenylalanine may help more with weight loss and vitiligo
  • DLPA may help with ADD in adults

If you’re struggling with chronic pain or substance dependence, D-phenylalanine might be the best choice.

How Long Does it Take to Work?

It depends on the condition, but in most cases, you can expect the first results after 2 weeks. The effects of DLPA may fade out over time, but it’s suitable for long-term use [26, 16, 18].


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DLPA supplements contain 2 symmetric forms of phenylalanine. They provide building blocks for proteins and neurotransmitters. Weak evidence points to their benefits for depression, chronic pain, and attention disorders.

Due to its L-phenylalanine content, DLPA may cause nausea and interact with Parkinson’s disease medication.

People with phenylketonuria, children, and pregnant women should avoid DLPA.

About the Author

Aleksa Ristic, MSc (Pharmacy)

MS (Pharmacy)

Aleksa received his MS in Pharmacy from the University of Belgrade, his master thesis focusing on protein sources in plant-based diets.


Aleksa is passionate about herbal pharmacy, nutrition, and functional medicine. He found a way to merge his two biggest passions—writing and health—and use them for noble purposes. His mission is to bridge the gap between science and everyday life, helping readers improve their health and feel better.

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