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Doctor's Best, Best D-Phenylalanine, 500 mg, 60 Veggie Caps

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In Stock
  • Expiration Date: Mar 2018
  • Shipping Weight: 0.18 lbs (0.08 kg)
  • Product Code: DRB-00110
  • UPC Code: 753950001107
  • Package Quantity: 60 Veggie Caps
  • Dimensions: 2.1 x 2.1 x 3.7 in, 0.15 lbs (0.07 kg)
  • This is the D-Phenylalanine form, not DL, or L form.

Product Overview


  • Science-Based Nutrition
  • Dietary Supplement
  • Suitable for Vegetarians

D-phenylalanine is a non-protein amino acid related to the essential amino acid L-phenylalanine. D- and L-phenylalanine are structural mirror images of each other. A small amount of D-phenylalanine may be converted to L-phenylalanine in the body. D-phenylalanine is reported to inhibit an enzyme that degrades enkephalins, which are naturally occurring substances in the body that belong to the class of compounds known as "endorphins".

  • Aids in the relief of minor pain

Suggested Use

Adult Use: Take 1 or 2 capsules daily, between meals.

Other Ingredients

Modified cellulose (vegetarian capsule), cellulose, magnesium stearate (vegetable source).

Contains nothing other than listed ingredients


Caution: Phenylalanine supplements should not be taken by individuals with phenylketonuria (PKU), children, pregnant or lactating women, people with high blood pressure, and anyone taking anti-psychotic medications or MAO inhibitors.

Supplement Facts
Serving Size: 1 capsule
Servings Per Container: 60 servings
  Amount per serving % Daily Value
D-phenylalanine 500 mg
† Daily Value not established.
iHerb Customer Reviews


Posted by 5347259314738162086 on Sep 08, 2016

I suffered from 1 year depression. I was taking 5-htp, with no results. But when I start to took 1 capsule of this in the morning, my depression did disappear in two days. Unbelievable.

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D-Best D-phenyalalnine works

Posted by Gibbly on Jul 02, 2016

Ups the receptors alright, taking two d-best d-phenys night time, one afternoon on empty stomach. Enjoy!

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Good Product

Posted by 4766872620965520922 on Jun 09, 2015

I have previously been taking precription antidepressants for about 10 years and have now chosen to stop taking them. I take one of these D-Phelylalanine 500mg tablets in the afternoon and one Jarrow SAM-e 400 tablet in the morning. This combination works well for me. I do not know if one is supposed to take these two preparations together or not but I decided to try it for myself. I am way less tearfull and in a much better mood from day to day. I feel much more like my old self. I am very pleased with the result. iherb stock great products at really good prices and deliver to New Zealand promptly - I am a very happy customer.

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Useful for emotional sensitivity and emotionally difficult times

Posted by 4871827516150754074 on Dec 08, 2013

I would have given this 5 stars, except for the fact that at 500mg it gives me this slight but annoying pressure headache and made it a little difficult to focus my eyes. At 250mg, it works best for me when I am going through an emotionally difficult time (DPA increases endorphins in your brain). It makes me much more emotionally at ease and much less bothered by whatever it is that is bothering me. I could see this as very useful for someone to take when they go through a relationship break-up or lose someone close to them. Just make sure you find the minimal dose that works for you. I open the capsule and pour half out then put the capsule back together and swallow it. I take it on an empty stomach and it works best that way. I also read that most studies have found DPA to be effective if taken every day at 100-200mg. So it seems kind of overkill to have these in 500mg capsules, although I'm sure for some people it is fine at that level. I first read about this in Dr. Priscilla Slagle's "The Way Up From Down" and then in Julia Ross's "The Mood Cure". They are both amazing books if you have depression and want a natural program that works even better than prescription medications. I have been following Slagle's basic program for two weeks now and haven't felt this good in years. Sorry for the rant.

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Helps with emotions

Posted by 4652840633200499013 on Nov 28, 2013

I began to use it after reading the the Diet Cure. Helps deal with life giving emotional support chemical-wise.

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