What Is 4-Fa? Is It Fun? Is It Safe?


Are you interested in 4-fa, also known as 4-fluoroamphetamine or 4-FMP? In this total guide to 4-fa, we’ll go over what this research chemical is, if 4-fa is legal, and if it’s safe. We’ll also discuss what taking 4-fa is like and how to procure and take 4-fa yourself while minimizing risk, including guidelines on 4-fa dosage.


What Is 4-Fa?

4-fa, also known as 4-fluoroamphetamine, para-fluoroamphetamine, and 4-FMP, is a research chemical or designer drug.

Research chemicals are synthetic, lab-created substances that have similar effects as existing illegal drugs. These chemicals are often synthesized in academic and medical labs for the purposes of medical and pharmacological research. But once information on how to create these chemicals becomes available through academic publishing channels, anyone with the right resources and tools can start cooking them up in their own lab.

4-fluoroamphetamine belongs to the phenethylamine and amphetamine classes. Like other amphetamines (for example: speed, meth, MDMA/ecstasy, and prescription drugs like Ritalin and Adderall), 4-fa is a stimulant. Stimulants make body systems more active. (This is why they are often referred to as “uppers.”)

4-fa is also considered an entactogen or empathogen, which means it provides feelings of increased empathy, emotional connectedness, and oneness with others. Thus, 4-fa is often described as providing an experience similar to a combination of MDMA, a notable entactogen, and a more traditional amphetamine.

It’s not clear who first synthesized 4-fa. Some sites posit that Alexander Shulgin, notable chemist and “godfather of psychedelics,” first synthesized 4-fa. However, he wrote extensively about his work synthesizing compounds in his books Phenethylamines I Have Known and Loved and Tryptamines I have Known and Loved, but he didn’t write about 4-fa. It’s certainly possible that he synthesized 4-fa, but there’s no solid evidence that he did.

4-fa appears as white crystals or crystalline powder. Its chemical formula is C9H12FN.


Jynto/Wikimedia Commons


Is 4-Fa Legal?

Research chemicals like 4-fa are typically considered part of the gray market. This means that while their sale is often not expressly illegal, it operates through unofficial and quasi-legal channels.

4-fa is currently an unscheduled substance in the United States. Unscheduled substances are not currently regulated by any federal government entities.

However, 4-fa may be an analog of para-Methoxyamphetamine (a.k.a. “PMA” or “Dr. Death”). This would mean that it would be illegal to sell for human consumption or possess with intent to ingest under the Analogue Act.

The Analogue Act is a federal law that makes it illegal to sell chemical analogues of Schedule I or Schedule II illegal drugs specifically for human consumption, or to possess one of these analogs with the intent of ingesting it (i.e. of doing it as a drug). No cases have been brought related to 4-fa sale or consumption under the Analogue Act, but it could theoretically happen.

Vendors get around the analog act simply by marking the substances as “not for human consumption.” Research chemicals like 4-fa are often sold under the guise of “bath salts,” “incense,” or other (non-edible) household products to maintain the legally useful fiction that they are not being sold as drugs.

The legal status of research chemicals can change fairly often. Drug laws are frequently updated to include new substances. In the United States, drug laws can vary from state-to-state. Even though it is unscheduled on the federal level, 4-fa is already expressly illegal in the states of Arizona, Florida, Louisiana, and Virginia.

4-fa is also illegal in the countries of Brazil, Canada, China, Croatia, France, Germany, Hungary, Israel, Italy, the Netherlands, Poland, Slovakia, Serbia, and the United Kingdom.

So is 4-fa legal? The bottom line is that it is expressly illegal in some states and countries, and has a gray or ambiguous legal status in many other places.

It’s also worth noting that some people favor research chemicals because they are often less likely to give a positive result for standard drug tests. However, because 4-fa is an amphetamine, you may test positive for amphetamines in a drug test if you have 4-fa in your system. So don’t count on its research chemical status to protect you. While not necessarily strictly a legal issue, testing positive for amphetamines could definitely impact your employment status.


“I assure you, Mr. Law Person, these mysterious crystals are just incense.”


Is 4-Fa Safe?

Is 4-fa safe for you to take? While no drug is completely safe, amphetamines like 4-fa carry a particular set of health risks to be concerned about. Amphetamines can cause anxiety, psychosis, rapid heartbeat, chest pain, extremely high blood pressure, dehydration, hyperthermia (increased body heat), jaw clenching and teeth grinding, and suppressed appetite.

Like other amphetamines, 4-fa has addiction potential. You may find yourself craving 4-fa or even re-dosing to stay high, which can lead to dangerous amounts of the drug in your body. Additionally, repeated use of 4-fa can cause you to build a tolerance, requiring you to take larger and larger doses to experience the same effects.

In addition to those side effects and risks, 4-fa can cause intense headaches and may increase risk of stroke, hemorrhaging in the brain, and heart failure. People on 4-fa have been admitted to the emergency room with very serious symptoms like confusion, suicidality, seizure, breakdown of muscle tissue, and an overheated body (hyperthermia). Snorting 4-fa can cause chemical burns in the nose and throat.

There have also been a small number of confirmed or suspected deaths related to 4-fa. Some of these may have been due to the use of multiple drugs simultaneously, which increases the danger associated with 4-fa.


There is danger associated with 4-fa.


What Is Taking 4-Fa Like?

So what is the 4-fa experience like? You should feel the effects of the drug fairly quickly, within an hour after taking it. Most people describe the initial high as “MDMA-like,” lasting for up to four hours. This then transitions to a more typical amphetamine experience lasting a few hours more. All in all, the high lasts anywhere from 6-8 hours, and you may feel after-effects for up to a day after (or rarely even longer).

There are a number of potential effects you may experience on 4-fa. You are unlikely to experience all of these effects during one 4-fa high, because everyone reacts to a particular drug a little differently. Your tolerance and the dose that you take will also impact your experience.

Here are all of the potential effects of 4-fa on your body: positive, neutral, and negative. We’ve also described potential after-effects of 4-fa.


Positive Effects

  • Euphoria; pleasurable tingling
  • High energy levels
  • Feeling empathy and affection for others
  • Suppression of anxiety
  • Increased sociability
  • Feeling of increased bodily control
  • Increased sensitivity to touch and texture
  • Color and pattern perception enhancement
  • Sense of increased focus and motivation
  • Libido increase
  • Increased appreciation of music
  • Heightened sense of humor


Neutral Effects

  • Lowering of inhibitions
  • Decreased appetite
  • Increased talking
  • Vibrating/twitching vision (nystagmus)
  • Increased sweating
  • Dilated pupils
  • Time distortion


Take 4-fa? Who, me?


Negative Effects

  • Insomnia
  • Difficulty maintaining an erection; difficulty reaching orgasm
  • Teeth grinding
  • Nausea
  • Headache
  • Dehydration and dry mouth
  • Suppressed temperature regulation/increased body heat
  • Heart racing/irregular heartbeat
  • Blood pressure increase
  • Muscle cramping
  • Seizure (greater risk at high doses)
  • Confusion


After Effects

  • These are symptoms you might experience after you come off of a 4-fa high:
  • Headaches
  • Anxiety, depression, irritability
  • Mental fatigue
  • Sensation of “shocks” originating in the brain (“brain zaps”)
  • Slow, disorganized thoughts
  • Lack of motivation
  • Insomnia
  • Suicidal ideation (most common at high doses)


If you want a more in-depth description of an entire 4-fa experience, read on for some trip reports excerpted from sites like Erowid, Reddit, and other drug forums.


You may need extra time in bed the day after you take 4-fa.


Positive Trip Reports

From Reddit user Tr1pleJay: “I found some from a good buddy of mine a few months ago and the experience was absolutely incredible. From my experience with MDMA I had never felt such pure bliss until I tried 4-fa. I have rolled on MDMA maybe about 5 or 6 times in my life, a couple times at raves, and STILL 4-fa kicked MDMA out of the water. A good 4 hours in, I took 1 more little cap(about .15 each) of 4-fa had my eyes jittering and I f***ing loved that, that was the most insane feeling for me, and i’ve never had the eye jitters before from Molly. Each experience on 4-fa was almost better that any experience I’ve had on Molly. My first 4-fa roll lasted a good ~9 hours since the comedown is very prolonged and smooth, and I loved every minute of it.”


From Bluelight user naginnudej: “+00:35 Delightful nervousness and warmth building in chest. I’m light on my feet.

+0:45 Getting chatty at this point.

+1:00-4:00 I’m impressed—undeniable entactogenic qualities with smooth stimulation keeps me on my toes. Work is accomplished with gusto and fervor; mixing music with a friend is particularly enjoyable.

+4:15-7:45 Entactogenic qualities have subsided although there is lasting stimulation for the remainder of the experience. Physical discomfort was nearly non-existent. MDAI would supplement nicely at this point (later proven to be true). Unable to sleep for ~12 hours after ingestion.”


These people had quite a party on 4-fa.


Neutral/Mixed Trip Reports

By Bluelight user BreakingSet: “I sampled this one twice at 150mg maybe two and a half years ago now. The first time was great. Dancing felt good, music sounded (and felt) good, very sociable and relaxed while being quite stimulated. I also remember sweating a lot.

Second time (same 150mg) I went bowling, and it still felt great, very euphoric. Until I came down that is. The next morning I felt like I had the flu, and felt extreme nausea if I stood up. I spent the next day and night in bed, and the next morning woke up feeling just a little cloudy.

I only mention this because there were other reports at the time that others were getting the same response after repeated use. There was talk that the compound may, or may not be slow to metabolize completely, lending to an unpleasant cumulative effect. I am not certain what conclusions were drawn. I know I threw mine away.”


By Erowid user SWIM: “Overall the experience was a disappointment, the mild euphoria first appeared at approximately T+0:40, this continued to build through the second dose reaching a peak at about T+2:00 but in no way compared with the intensity of a good roll or the explosive energy of 4-MMC.

By T+4:00 the euphoria had completely died away and although heart rate was a little fast, it was like a few strong cups of coffee. So SWIM retired to bed and with a couple of sleeping tablets slept well and awoke the following morning feeling no after effects other than a general tiredness as might be expected. There were no bitten gums, very little dilation of the pupils, all in all a very unstimulating experience.”


From Erowid user Bear Claw: “Now, regarding the actual experience. This is a very mild feeling stimulant. I would agree with some folks claiming it to be reminiscent of MDMA, but only because I don’t know what else I would compare it to. I would say you’re not going to feel like a rockstar, as is the case with coke and meth. You’re also not going to experience that ‘OH MY GOD I LOVE EVERYTHING THE WORLD IS MADE OUT OF MAGIC’ feeling as with MDMA.

The actual high is quite clear headed and subtle. There are body tingles and a somewhat limited euphoria towards the beginning. After the initial ‘rush’ (if you can call it that) wears off, I was in for about 12ish hours of gentle stimulation. I found myself feeling pretty neutral for most of the night, which is weird for this kind of drug. I was not motivated to clean, or organize, or really do anything or go anywhere. It feels actually pretty lethargic. There were also occasional flashes of feeling irritated and annoyed. I was able to think clearly and more or less rationally. Words came easy, and writing in my journal was enjoyable. I played guitar for a little while, which was definitely more fun than usual, but attempts at writing new songs were unsuccessful. Don’t expect to feel exceptionally creative or spiritual. It’s just not that kind of drug.

My roommates were sort of in and out of the house for the duration, and I did not enjoy their company. Generally on stimulants I’ll talk a mile a minute at anybody within earshot. 4-FA made me wish, for the most part, to be alone. I imagine it would be different if I had taken this with friends, and conversation probably would have been fun with people also under the influence. I tried this alone to gauge the experience before introducing it to anybody else. For science!

It seems to be pretty easy on my body. I don’t feel ‘f***ed up’, and the experience sort of slowly levels off until the end of the night. I was able to sleep with the help of a few beers…All in all, I enjoyed the experience, and I will be trying this again.”


Kitty is not super impressed with 4-fa.


Negative Trip Reports

From Drugs-Forum user KoBe: “So, don’t play with this stuff like it’s meph or something, because it’s f***ing strong. We did 5 lines of this stuff (2.5 cm long each) with friends, and yes it was godlike, but 3-4 hours past, it was kinda hell. We also smoked 6 joints, and that is where it went fucking crazy. Everyone had low pressure. One of my friends passed out while washing his hands. Memory was f***ed up beyond anything. Next day, vacuum in brains. Next week after, still kinda damaged. It also intensified my HPPD since then, and seriously f***ed up my sleep pattern.”


By Erowid user exopian: “Paranoia is coming in waves. It’s quelled with a bit of self-centering.

T + 37 hours : Paranoia waves have subsided, and I finally manage to eat a meal. The meal and break from tasks come as a pleasant reprieve for both mind and body.

T + 45 hours : I finally start to wind down, and get a hot shower. This is incredibly relaxing, and I fall asleep easily.

T + 48 hours : I wake up feeling absolutely dreadful. My kidneys hurt. There is terrible nausea. Despite being exhausted, I cannot quiet the cacophony of painful echoes that ambient light and sounds seems to trigger. I drag myself up out of bed and fix a cup of ginger tea. Anything with more weight than that sounds putrid. I decide that I’m going to detoxify.

T + 49 hours : The dread has subsided, and I feel incredibly light-headed. I don’t know how much this has to do with nutritional deprivation, and how much of it is to do with the drug. Regardless, I manage to drink a soda and a few glasses of water.”


By Erowid user Meilikhios: “Physically it felt like a cross between being stoned and having the flu. Sometimes some chills showing up. There was also some moderate hyperthermia as often with amphetamines. Moderate heartbeat acceleration. Mentally, there was a kind of matter of fact calmness, an emotional smooth bluntness so to speak, a tinge of cannabis-like stoning and some psychedelic-like emotional sensitivity. There was no mood lift in sight and in fact a mood that was slightly grim/sad and neutral at the same time. Pupils were dilated.

After 6h I could still feel it but it was very weak and subtle, almost residual. It was never unpleasant nor threatening, but it wasn’t pleasant either. It just was. There was also a faint anorexia but i ate a pizza nonetheless (I was having dinner in a restaurant with friends). Dry mouth for sure. Mini me was out to lunch. I went to sleep at about T+7h without much problem.

The next day (ie now at T+21h ) I had chills and even goose-bumps from time to time which have eventually subdued. I also have some aches coming and going on my ears, fingers and temples and my kidneys don’t feel in their best of shapes. There is still a persistent anorexia (still haven’t eaten) and i feel a touch of nausea could show up if I were presented food. A slight mental spaciness and I really still feel as if I have the beginning of a flu. My head feels weird, almost absent. I’m not in my best of moods either, kinda down and a bit fragile physically and mentally.

All in all it’s not a pretty picture. It was boring, nothing interesting at all, just a waste of time.”


This dog had a very “ruff” time on 4-fa.


How to Take 4-Fa: 8 Steps

If you do decide to take 4-fa, there are ways to minimize your risk. We offer an eight-step process here to help you have the least dangerous 4-fa experience that you can.


Do Research on 4-Fa

When you are considering taking a new drug, the first thing you should do is research that drug much as possible. This article is a good start. However, you can (and should!) also examine the information available on sites like Erowid and Psychonaut Wiki. These sites offer curated and crowd-sourced information on 4-fa, including lots of trip reports. The founders of Erowid, Earth and Fire Erowid, take a harm-reduction approach to drug use and are dedicated to making accurate information on drugs more freely available.

Reading a variety of trip reports will prepare you for taking 4-fa by helping you know what you can expect from the drug—both good and bad. Doing research will also help you figure out proper drug dosage.

Note: if you have a heart condition, do not take 4-fa as it may cause heart problems.


Obtain 4-Fa Safely

Sourcing your drugs from a reliable, trustworthy vendor is important. This way you can be reasonably confident that you are really buying 4-fa and not some other drug (see our section below on where to buy 4-fa). Ingesting a different drug than you intended is very dangerous and may even be life-threatening, especially if the drugs have very different recommended doses.

4-fa comes in the form of white crystals or powder. Unfortunately, lots of drugs look like this. If you ever are not sure if you’ve gotten the drug that you ordered, ask people on forums like Erowid and Reddit for advice on how to check if you really have 4-fa. And lastly, if you are at all in doubt as to what drug you actually have, don’t take it!


Figure Out Your 4-Fa Dosage

Next, you’ll need to decide how much 4-fa you want to ingest. Your best bet for taking 4-fa is ingesting the drug, preferably in gel caps. Snorting it can cause serious chemical burns in the nose and throat and is not recommended.

Here are the recommended 4-fa dosages from Psychonaut Wiki for oral administration:

  • Very light: 20-40 mg
  • Light: 40-80 mg
  • Standard: 80-120 mg
  • Strong: 120-140 mg
  • Heavy: anything 140+ mg

Bear in mind that these dosages may vary somewhat based on your weight and personal tolerance for amphetamines. If you’ve never taken 4-fa before, it’s safer to try a lower dose for your first time. It’s also critical to measure your dose correctly. You may need to invest in a very accurate scale.


Proceed with caution when you select a dosage!


Get a Sober Friend

Find a friend you trust to stay sober and monitor your status during your high. They can help make sure that you don’t do anything you shouldn’t (like drive), help you stay hydrated, and seek medical attention on your behalf if necessary.


Choose the Right Time and Place

It’s important to do 4-fa at a time and place that are most safe for you. Some people like to go to social gatherings when they are on empathogens and/or amphetamines, and 4-fa is both. However, you’ll be safest if you go to a familiar location with people you know. A house party at a friends house is a better choice than a giant warehouse rave or stadium concert. This way your surroundings will be familiar and it will be easier for your sober friend to keep track of you.

Also, you should be aware that you may not be able to sleep for many, many hours after you take 4-fa. It will probably mess up your sleep schedule, so make sure that your schedule can reasonably accommodate the difficult sleep adjustment that is likely to follow.


Eat in Advance and Hydrate Throughout

Eat a robust, healthy meal within a couple hours of taking 4-fa. While taking 4-fa on a fuller stomach will slow the initial absorption of the drug, it’s important to get some calories into your body before taking it. This is because it’s likely that you won’t want to eat for the duration of your high, and maybe even longer.

You should also be sure to drink lots of water throughout your high, even if you don’t feel thirsty (your sober friend can help with this). This will help you stave off severe dehydration and its accompanying unpleasant symptoms.


Don’t Re-Dose or Combine With Other Substances

You may be tempted to take another dose when the effects of 4-fa start to wear out, to keep the high going. However, this can increase the amount of the drug in your body to unsafe levels and is not advised.

You might also want to combine 4-fa with other substances. In general, it’s very hazardous to combine stimulants with other stimulants because the effects may compound and cause a dangerous increase in blood pressure and/or heart rate. It’s also dangerous to combine alcohol with stimulants as this can lead to unsafe levels of intoxication. Tramadol combined with 4-fa may increase the risk of seizures.

Additionally, combining 4-fa with MAOIs, drugs that release serotonin (like MDMA), SSRIS, and SNRIs may increase your risk of serotonin syndrome. Serotonin syndrome describes the release of neurotransmitters to unsafe (or even life-threatening) levels.

The bottom line is that it’s safest to just stick to one drug at a time. Otherwise you may experience the effects of an unexpectedly dangerous or even life-threatening drug interaction.


Be Ready for the After-Effects

4-fa can cause unpleasant after-effects as long as multiple days after you take the drug, including anxiety, depression, insomnia, and headaches. Be aware that if you take the drug on a Saturday, you may still feel pretty bad on Monday. You’ll recover more quickly if you drink lots of water and eat some calories. If you aren’t hungry, try having a smoothie.


Consider stocking up on smoothies in advance.


Where to Buy 4-Fa

4-fa may be harder to get your hands on than other research chemicals because it’s already illegal in several countries and a handful of states. If you’re looking to buy 4-fa, I would look on Reddit for the most reliable place to buy 4-fa that is still shipping to the United States.


The Bottom Line on 4-Fa

4-fa is a research chemical that is an amphetamine and a phenylethylamine with entactogenic properties.

4-fa is legal to possess in some states in the United States, but most likely illegal to sell or possess for human consumption. It is illegal in a handful of countries and some US states due to concerns about its safety.

Concerns about 4-fa drug safety include that it increases risk of stroke, heart failure, and hemorrhaging in the brain. Several people have died in connection with 4-fa consumption.

People describe the 4-fa experience as starting out somewhat similar to MDMA, with feelings of connectedness and empathy for others. After a few hours, it transitions to a more typical amphetamine experience, with heightened energy and focus.

If you do decide to take 4-fa, here’s how to minimize your risk of serious harm:

  • Research 4-fa thoroughly first; read lots of trip reports.
  • Obtain the drug safely, and don’t take it if you aren’t sure that you have 4-fa.
  • Figure out the right 4-fa dosage. Err on the side of lower doses.
  • Get a sober friend you trust to monitor you while you are high.
  • Choose a time when you can accommodate the unpleasant aftereffects of 4-fa, and a place that’s not overly unfamiliar.
  • Eat before you take 4-fa and drink water throughout your high.
  • Don’t re-dose 4-fa or combine 4-fa with other substances. These things dramatically increases your risk of serious injury or death.
  • Be ready for the after-effects.

If you still have your heart set on a 4-fa experience, you do need to obtain the drug. It may be harder to get 4-fa than many other research chemicals because 4-fa is affirmatively illegal in a handful of places. However, you can look to Reddit or other research chemical-themed forums for recommendations.


What’s Next?

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