D-Phenylalanine vs. L-Phenylalanine: What’s the Difference?         

DL-Phenylalanine or DLPA is one of the top mood-boosting supplements available today. It gives you the combination of L-Phenylalanine and D-Phenylalanine, two important forms of the same compound. Many people take this supplement to improve their mood and attention. However, what about the comparison? If we compare D-Phenylalanine vs. L-Phenylalanine which one comes on top? In this article, we’ll explore the two different forms of Phenylalanine and how they work in your body. We also look into the different benefits that users experience when they take a combination form – DL-Phenylalanine. [caption id=""attachment_1689"" align=""aligncenter"" width=""640""] DL-Phenylalanine is great for improving mood and focus[/caption]

What do the D- and L- stand for?

D- and L- are what chemists use to donate substances that are mirror images of one another. The different mirror images of a chemical compound are called enantiomers. In the case of D-Phenylalanine vs. L-Phenylalanine, ‘D-’ stands for a right-hand twist and ‘L-’ stands for a left-hand twist. Different twists in chemical compounds and substances can result in dramatically different effects in our bodies. This is why it’s important to compare D-Phenylalanine vs. L-Phenylalanine.  

What is D-Phenylalanine?

D-Phenylalanine is the right-hand twist of the Phenylalanine compound. D-Phenylalanine is a laboratory-made substance with a number of potential benefits. It is first converted into tyrosine which is then converted into dopamine, epinephrine, and norepinephrine.[1] This is why it is thought to help promote a healthy mood and maintain mental focus. One of D-Phenylalanine’s main benefits is its potential to help with pain relief. D-Phenylalanine is an inhibitor of the enkephalinase enzyme. Enkephalins are part of your body’s natural pain relief system. When they are broken down by enkephalinase, this contributes to the sensation of pain. D-Phenylalanine is specifically thought to be beneficial for reducing feelings of chronic pain.[2]  

What is L-Phenylalanine?

L-Phenylalanine is the ‘left-hand twist’ version of Phenylalanine. It is an essential amino acid and the naturally occurring form of Phenylalanine. Essential amino acids are molecules that our body requires as building blocks for proteins and cannot manufacture itself. Phenylalanine is an important amino acid for building proteins and maintaining a healthy body.[3] Studies have found that people who are low in L-Phenylalanine have lower moods. In one study, healthy women consumed a diet that was low in Phenylalanine. The results showed a significant decrease in mood ratings.[4] This is why it is suggested that high doses of L-Phenylalanine supplements can help to improve and sustain a good mood.  

What is DL-Phenylalanine?

[caption id=""attachment_1042"" align=""alignright"" width=""300""] Liftmode's DL-Phenylalanine, 99% purity[/caption] DL-Phenylalanine is the combination of both L-Phenylalanine and D-Phenylalanine. Taking a DL-Phenylalanine supplement allows you to access the benefits of both the Phenylalanine enantiomers as well as some other benefits. Often, people find that it is more beneficial to take the two together instead of weighing up the pros and cons of D-Phenylalanine vs. L-Phenylalanine. It seems that when you take D- and L-Phenylalanine together, they work synergistically to provide extra benefits. One of these benefits is an increased mental focus and attention. A number of studies have looked at the focus-enhancing properties of DL-Phenylalanine and they seem very promising.[5]  


So, D-Phenylalanine vs. L-Phenylalanine – which one is better? Well, it seems that they both have their own unique benefits. L-Phenylalanine is the natural form of Phenylalanine and is important for building proteins and maintaining a healthy mood. D-Phenylalanine is the laboratory version and is important as a pain-relief substance. When taken together, DL-Phenylalanine has great benefits in improving focus and attention.    

Medical Disclaimer

Not intended to treat, diagnose, or cure any disease or ailment. Please read and fully understand potential adverse effects before using this product. These statements have not been reviewed by the FDA and are not written by a medical professional. Please consult your doctor before using any supplements, especially if you have any medical conditions.


B.Sc. in Molecular Biology and Biochemistry Researched & written by Tristan and verified by the Liftmode.com Research Team


[1] D-Phenylalanine, PubChem Open Chemistry Database, retrieved on December 8, 2016 [2] Analgesic effectiveness of D-phenylalanine in chronic pain patients, NE Walsh et al., Arch Phys Med Rehabil. 1986 Jul;67(7):436-9. [3] L-Phenylalanine, PubChem Open Chemistry Database, retrieved on December 8, 2016 [4] Effects on mood of acute phenylalanine/tyrosine depletion in healthy women, M Leyton et al., Neuropsychopharmacology. 2000 Jan;22(1):52-63. [5] Treatment of attention deficit disorder with DL-phenylalanine, DR Wood et al., Psychiatry Res. 1985 Sep;16(1):21-6.    

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