The nootropic PRL-8-53, a synthetic supplement has potential benefits as a powerful intermediate term memory booster.

Currently marketed as a nootropic research chemical, PRL-8-53 (named for Pacific Research Labs, the entity who owned the patent for the drug until its expiration) is derived from phenylmethylamine (Benzylamine) and benzoic acid.

This nootropic compound was invented by Dr. Nikolaus Hansl in 1970. The public was first made aware of the potential effects through published findings of various animal studies conducted between 1970 and 1974.

The only human study was published in 1978.

The effects of PRL-8-53 on learning and on the retention of certain verbal information in human subjects was confirmed. The study concluded that there were improvements in the following areas:

  • General word acquisition
  • Intermediate term recall
  • Intermediate retention of verbal information

Alternative Names

3-(2-benzylmethylaminoethyl) benzoic acid methyl ester hydrochloride, PRL- 853

Editor’s Note

Due to lack of data on dosage and long term effects, I have not taken this nootropic drug. However, there is a lot enthusiasm for the potential uses of PRL-8-53 in the nootropic’s community, at large.

Anecdotal evidence is that users report positive outcomes from taking PRL-8-53 with no immediately discernible side effects or adverse reactions.

The demand for viable and potent nootropics has led users to seek long forgotten compounds, such as those created by Dr. Hansl.

This pull from the community has impacted the supply of such experimental compounds and will continue to propel studies into their usefulness, efficacy and long-term safety.

This is a wonderful thing for those interested in bringing nootropic research on supplements and novel synthetics to the forefront, though research efforts will likely remain small and independent.

The public’s demand for research-grade substances is evident in the fact that this nootropic is available for purchase, though, with the following caveat displayed by one compounding site.

“*This compound has not been approved by the FDA and should be used for research purposes only.”

During my research, I found references to several articles or interviews, in which Dr. Hansl discussed the findings of independent studies he conducted over the years. I was able to verify one such article from 1979 which I cited in a subsequent section of this review.

Unfortunately, Dr. Hansl passed away in 2011 with much of this research unpublished and thus unverifiable.

Interestingly, an enthusiastic group of indie researchers have contacted Dr. Hansl’s daughter and plan to obtain his research papers with hopes of continuing where he left off.

Due to the limited availability of information, our review of PRL-8-53 is based largely on four sources:

  1. Results of a single double-blind, randomized human study of PRL-8-53
  2. Peer reviewed article published in 1979
  3. Anecdotal or social proof found throughout the Internet including reputable Nootropic community sites.
  4. Information from the patent application for PRL-8-53

PRL-8-53 Reviews

Return to PRL-8-53: A glowing report

“On PRL-8-53 (10-20mg), my working memory is both massively improved and effortless. In lecture, I can easily play back the last 20-30 seconds in my head (word for word, exact intonation) and very rapidly link written words to concepts — which, in theoretical math and statistics, is easier said than done. My ability to quickly read, understand, and connect research publications is greatly improved due to the improvements in working memory, as I can now (exactly) automatically remember a couple sentences back rather than a few words.” – Anonymous – 2015

PRL-8-53 – Ridiculously Powerful Memory Enhancer:

“I started out with small doses and worked my way up to larger quantities. (…) I decided to try 20mg on Friday for my Neuroscience test and was amazed by the enhancement in recall I had. Up to that point I had not really felt too big improvement in memory or recall, but after that test I knew that it was working. For me I felt that the larger doses definitely helped on recall and was a huge help for tests. Also it seems that it is best taken 30 minutes before whatever you need it for Overall I definitely saw results and had no issues with with other nootropics that I take regularly.” – (Reviewer) baliflipper

In his book, Life Extension: A practical scientific approach, Warner 1983, longevity expert Durk Pearson talks about similar nootropic compounds and was quoted in an article in High Frontiers as saying:

“PRL-8-53 is a terrific memory enhancer. Normally you can memorize about seven or eight digits just by looking at them for a second. PRL-8-53 gives the average person a memory span of about 21 to 22 digits.”

Known Benefits


PRL-8-53 is thought to improve intermediate to long term memory.

In the published study for PRL-8-53, there was evidence of improvement in long-term “word acquisition” during a memorization task.

The study participants were first dosed with 5mg of the compound then two hours later; they were asked to listen to a recording of 12 previously unknown words.

As the study progressed, 80% of the participants were able to remember and correctly recite the words in order, after a period of 4 days had passed. A similar impact on memory was not observed in the placebo group.

There was also a benefit noted in the participant’s ability to memorize in the short term, as well. Though the results were too similar to the placebo group, the findings were largely discounted.

Unpublished Benefits

Geometric Pattern Exercise

In literature submitted with the patent application, the compound creator Dr. Hansl refers to additional research which has never been made available or published, that indicate the improvement in the ability to recreate spatial and geometric drawings.

This effect is also mentioned in a journal article published in the Phi Delta Kappan, (v61 n4 p264-65 Dec 1979) entitled, Learning and Memory Improvement through Chemistry: Dream or Reality in the Offing?, Dr. Hansl mentions that PRL-8-53 showed a statistical improvement in scores on a series of geometric pattern cognitive exercises. In this article, PRL-8-53 was described as,

“an experimental drug that will boost the chemical system in the brain called the cholinergic system and thereby improve one’s ability to retrieve information from a preexisting knowledge pool.”

Improved Mathematical Abilities

In the same article, Dr. Hansl mentions a mathematical exercise in which participants were asked to perform addition and subtraction processes until a particular number was reached. Shorter times in reaching the “goal” number were noted in the group using PRL-8-53.

Improved Verbal Fluency

In the same report, Dr. Hansl recalls a test in which participants were asked to create words using a series of letters.

He said that there was statistically significant improvement observed in participants who had taken his compound.

How It Works

The mechanism of action for this nootropic is largely unknown but may be related to the cholinergic properties.

In the Phi Delta Kappan journal article, Dr. Hansl, speaks about how he believed PRL-8-53 enhanced the brain’s the response to acetylcholine. He pointed out that he did not consider the compound to be a stimulant.

In the patent application for PRL-8-53, Dr. Hansl mentioned the following:

“An animal test involving rodents showed 4 mg/KG increased apomorphine (dopamine agonist) increased compulsive gnawing in rats.”

This indicates that PRL-8-53 exhibits the properties of a dopamine agonist. This classification of drugs is commonly used to treat neurodegenerative disorders like Parkinson’s Disease.

Also from the patent, we learn, “this nootropic does not enhance amphetamine’s actions in rats and doesn’t appear to inhibit MAO activity.”

In the single human trial, Hansl mentions that PRL-8-53 “potentiates dopamine release and causes partial inhibition of serotonin”

Known Side Effects

In human trials, a standard 5mg dosage caused no side effects

The patent for PRL-8-53 mentions the compound is well tolerated in dogs and monkeys at up to 50 mg/kg.

In rodents, reduced motor activity was noted in high dosages.

User-Reported Side Effects:

The online community reports the following common side effects for PRL-8-53

  • Night sweats
  • Overheating
  • Vivid dreams


The effective dosage may vary. In human studies, PRL-8-53 was given a single dose of 5mg, orally, and was not based on weight.

However, patent information on PRL-8-53 does suggest a therapeutic dosage range of 0.01 – 4 mg/kg taken by mouth. More evidence and empirical testing are needed to determine an ideal dosage for PRL-8-53.

Based on the limited evidence, it appears that PRL-8-53 is well tolerated at a relatively large therapeutic threshold. However, toxicity studies in humans and rodents are not available.=

While there are indicators throughout the literature that other routes of administration might be more beneficial, the oral route was the only one Dr. Hansl provided dosage information concerning.

There is nothing to indicate a preference, one way or another, in taking with food.


There are no studies, human or animal trials involving the use of concurrent dosing with other supplements.

However, a review of online social self-reports indicates the following supplements can be taken with PRL-8-53 with added benefit or without additional side effects.

  • Memantine
  • Magnesium
  • Alpha-gpc
  • Creatine
  • N-acetyl
  • Semax
  • Selank
  • B12
  • Sunifiram
  • SEN-12333
  • Phenylpiracetam
  • IDRA-21

Alternatives to PRL-8-53

The following nootropics have been shown to effective in enhancing short, intermediate and long term memory.

Alpha GPC

One of the best choline sources available as a supplement, Alpha GPC is known for boosting focus and concentration.

However, because it works so synergistically with other nootropics, it specifically boosts overall function including short term and long term memory.

To learn more about this supplement you can check it out here.


It may be best known for as a powerful mood enhancer, but it also significantly improves memory, as well. Regular users agree that it provides a myriad of short-and long-term cognitive and memory benefits.

To discover if this is the right supplement for you, check out this additional information.


More potent than Piracetam, it packs a stimulant punch while providing significant cognitive effects. Often compared to the prescription ADHD medication, Adderall.

It is one of the most powerful non-prescription nootropic supplements on the market today. One of many benefits of Sunifiram is its ability to enhance short and long-term memory, as well as increasing productivity.

To find out more about the most powerful non-prescription supplement on the market click here.


CDP-choline or citicoline are an excellent combination that works well with most types of nootropic supplement in the racetam class.

Citicoline works by producing more of the naturally occurring acetylcholine or neurotransmitters which are responsible for improving the cognitive processes used in memory.

Could Citicoline work for you? Find more information here.

Where to Buy PRL-8-53?

Currently, there are only three places online to purchase prl-8-53. Additionally, you can find it on Amazon, facilitated by two of the three sources listed here:



As nootropics go, PRL-8-53 is a bit of a mystery. It has exciting potential in terms of a pharmaceutical grade synthetic compound, that has undergone basic testing.

However, much is not known regarding long term effects and accurate dosage and administration.

The sheer enthusiasm surrounding the re-discovery is bringing about important discussions. Social proof tends to back up the inventor’s claims of improved memory and mathematical reasoning.

For those willing to take a risk on a largely untested compound, the rewards might be significant. This reviewer will wait, preferring to use more safe alternatives, for now.