Home > Diets > Diet Supplements Diet Navigation    
User Rating

This diet does not have a rating because it does not have enough votes.

+ - Tried it? Rate it!


This Phentermine diet pill claims to boost metabolism and suppress appetite.

Top Rated Diet Pills of 2022
QUICK FACTSQUICK FACTS Start the Diet Now Advertisement
  • Established: 1959 FDA approval; available in the 1970s; removed from the market voluntarily in 1997 but still available
  • Founder: Originally sold by King Pharmaceuticals; currently made by several companies
  • Accessibility: Prescription only
  • Diet Type: Appetite suppressant to be taken short-term
  • Gender: Male and female

Do You Know the Best Diet Pills of 2022?


In December of 1998, the pharmaceutical giant, SmithKline Beecham withdrew Fastin from the market because of side effects associated with this weight loss supplement. Today, it is back on the market, as it tries to help those who are obese lose weight. Phenylethylamine, or Phentermine, is the main ingredient in Fastin. This chemical is a powerful stimulant that boosts metabolism, suppresses appetite and raises heart rate.

Fastin should only be used by people who are extremely overweight or obese and have not been able to lose weight with just diet and exercise. Fastin should only be taken under the supervision of your doctor. It should also be taken in conjunction with a reduced-calorie diet and a consistent exercise plan that has been laid out for you by your medical doctor or registered dietitian.

Fastin contains stimulants that may cause side effects like increased heart rate, shakiness or heart palpitations.

  • Fastin may help to kick off a weight loss program
  • May help to reduce weight when used in combination with a low calorie diet and exercise plan
  • Fastin was pulled off the market in 1998
  • Not a long-term solution to weight loss
  • Can induce many dangerous side effects
  • Should not be taken by certain individuals who have current health conditions
  • Should not be used for longer than a few weeks
  • Can result in dependence
  • Automatically enrolled in the auto-shipment program after registering for free trial

Fastin contains Phenylethylamine HCL, R-Beta-Methylphenylethylamine. methylphenylethylamine tartrate , methylsynephrine HCL , N-Methyl-phenylethylamine HCL, Synephrine HCL, Theobromine Anhydrous, Yohimbine HCL and caffeine.


Given the powerful effects of Fastin, it should only be taken according to the directions of your medical doctor.

Fastin is typically taken once a day 1 hour before breakfast or as directed by your doctor. Since it contains stimulants, you should not take it before going to sleep. Also, Fastin should only be used for a few weeks since it has the ability to result in dependence.


While taking Fastin, you will also be following a reduced-calorie diet comprised of 1,200 – 1,500 calories a day and a consistent exercise program that is laid out by your health practitioner. You should avoid alcohol, caffeine and any other stimulants.


Fastin is a stimulant that works in a similar way as amphetamine. In addition to being an appetite suppressant it is also a mood-elevator. Fastin should only be used by people who are obese and under the supervision of their medical doctor.

It is not recommended for use by individuals at risk for diabetes, high cholesterol levels, high blood pressure, a malfunctioning thyroid, hardening of the arteries, or heart disease or if certain medications are being taken.

Common MisspellingsCommon Misspellings

Fasten, Fastin Diet Pills, Phentremine, Phentermine, fentermine, Adipex-P, Ionamin, Obenix, Oby-Cap, Teramine, Zantryl

How Does Fastin Compare?
  • Product Name
  • User Rating
  • Has Good Appetite Suppressant
  • Has Only Natural Components
  • Contains No Coffee
  • Fastin
  • /100
  • .
  • .

> Leave Feedback

User Feedback

(Page 1 of 2, 38 total comments)

Beka Cox

I use to take this an it works even witout exercise an acorse it would have been even better if had. . M . An now i am thinking on tryin it again an they say u have to be obiest or over 50 POUNDS well im not i wasnt than either so i think its like anything else take in moderation like ur suppose to

posted Nov 16th, 2017 1:16 am



I purchased this product a few days ago and the first day I took one and about thirty mins later I was so jittery and my hands were shaking so badly it freaked me out. O also felt alittle sick. I had been on phentermine before and it never felt this strong. I told myself that the next day there would be no way I would take a whole pill. So I tried just a half after I ate. This worked much better for me. Although still alittle jittery, it wasn't as bad. It does give you energy and curve your appetite. I'm just gonna stick to half pills from now on until I feel it may not be working anymore, but so far it is. What a boost of energy.

posted Jan 22nd, 2016 4:00 pm



I just started it a week ago. I started it with one pill after breakfast and one after lunch, then increased to three a day. How ever, I felt weird since the start! Headaches for the most part, and starting yesterday- HORRIBLE shakiness and trembling! I was sweating one minute then ice cold the next. I couldn't focus at all and had a sore throat. I had better be losing weight with this....ugh.

posted Apr 23rd, 2013 2:15 pm



I have taken FastinXR, on and off, for one year and a half, successfully. I only take 1capsule in the morning, then 1 around 3pm. I've made the mistake of taking much later...don't do that, as you may find it hard to sleep! I get mine from GNC. If you want to know how these work for you, I would suggest buying from them, as they have a 30-day money back guarantee on what you buy, even if the bottle is opened. I had previously been on rx phenteremine, with absolute success, I might add. But, when I lost all my weight, size 12 to size 6, my doctor began to make excuses to not prescribe anymore - I have a great doctor, she did as she is suppose to. But, I got into a major car accident,wasn't able to walk for 8mo., and began to gain some of my weight back, when I found these capsules at GNC. I couldn't take them, at first, because of all the other heavy rx pain killers I was taking. So I held on to them until after I had major back surgery in June 2012. Once I got off the rx pain killers, I began taking them again, as I had gained a lot more weight from being ambulatory, getting up size 10. Since, August, I've been consistently dropping back down without any extra exercise. Just to add, I'm still not working and trying to get back to walking normally again. They do change my mood,for the better, really suppress my appetite, and give me tons of energy.

posted Dec 11th, 2012 2:50 pm


I am starting with that product tomorrow. I will see... One year ago I had Adipex and it worked great. In40days I lost more than 20lbs. I am looking forward to Fastin-XR.

posted Apr 27th, 2012 6:15 am


I love this product I started on it 7 days ago, I took one pill for the first two days and then two pills a day there after...I went from 173 to 165 in 6 days. They pills total took my appetite away, and gave me tons of energy. I noticed I did sweat alot to the point where I had to change my shirt. Also I might add I lost the weight with absolutely no EXERCISE!!!! this week I will exercise and see how much I will lose. If your sensitive to caffeine be careful. This pill is the best, I'm gonna try Fastin xr the extended release to avoid taking so many pills a day, since they are a little stronger.

posted Apr 23rd, 2012 9:45 pm



LOVE it! Mood enhancer and appetite suppressant.

posted Apr 3rd, 2012 4:29 am


I messed around and took it yesterday around 6pm for the first time... wont do that again!!!! couldnt sleep at all. I have taken it again this morn tho and feel great. We will see how it goes... 40 lbs to go!!!!

posted Mar 7th, 2012 5:39 pm



I took this and lost 26 lbs in two moths and have been able to keep it off since november

posted Feb 28th, 2012 11:34 pm


Starting it today, i want to lose 50-55 lbs. lets see what happens.

posted Feb 24th, 2012 3:52 pm


Ok I started taking Fastin this morning. Took my first pill at 10:00 am. I am a coffee drinker so I avoided the coffee and ate a very small breakfast. The pill hit my system fast. I got the sweats and slight jitters. Sweats were small but I had to check to make sure my deoterant was working. Then the after taste of the pill hit. Nasty. About 45mins later zing to the moom Alice. Wow, I had to ask God to forgive me I haven't felt like this since I smoked weed as a teen. Not hunger at all, but need to eat to avoid the head aches. I do want to lay down though I feel like i want to sleep but have energy at the same time. I plan to take the pill for 30 days so come back each day except weekends to see updates.

posted Feb 15th, 2012 5:30 pm


i took Phentermine before I knew was pregnant and my baby was born with birth defects has this happened to anyone else?

posted Feb 14th, 2012 6:05 pm



I used years ago and had good success. you can loose weight and feel good at same time, but everyone needs to know this as any medication takes a good 3-7 days to get into system and start to work, don't expect to take it and lbs fall off. work with it, if you feel that bad STOP taking it. I am gonna do it again

posted Jan 17th, 2012 9:41 pm


I have used Fastin before a few years ago with a diet and excersise plan, and it worked very well. My doctor checked to make sure it was safe for me, and I followed her suggested meals and exersise regimens and got good and safe results. Its probably different for different people and not good for some people.

posted Jan 13th, 2012 5:12 am


I just started this drug yesterday. So far I have had major headaches, my blood pressure has gone up, I am nauseous and am sweating out of every pore in my body! I thought I would use something to jumpstart my weight loss as I have 4 children and my last pregnancy caused my pubic bone to separate. I still, after 14 months, have incredible pain. However, I am thinking a little chub is better than feeling like crap!

posted Jan 3rd, 2012 3:34 am


My husband took this pill to loose a few pounds along with his work out plan. it made him crazy, he became very depressed and angry. He is a very optimistic person and always happy and in a good mood. Soon after he would take the pill each day he would get frustrated over the smallest things, he said he felt violent, sad, and like nothing could hurt him all at the same time. On days he wouldnt take the pill he would be back to his normal self even at night once the pill wore off he would be normal. It does curb your appetite but can be dangerous to people who have other health issues. (THIS IS A DRUG) Please use with caution!!!!

posted Dec 29th, 2011 1:31 am



I have lost 10 pounds in 3 weeks. I am disabled and am not able to really work out. With Fastin I am finally losing weight. I have to lose weight for my health. I bought my Fastin at Walgreens for $20.00. I am off of soda, coffee, and do not crave sweets. My sweet tooth is finally under control. My thyroid Dr approved of me taking Fastin. After taking it for 3 weeks and losing 10 pounds my triglycerides have gone down almost 200 points.

posted Oct 24th, 2011 4:08 pm



Just started taking Fastin today. I'm 178.4 lbs and i'd like to be some where around 120 - 125 within six months. Hopefully I will reach my goal. I'll check back in a couple days.

posted Aug 27th, 2011 1:38 am



BE WARNED. I took this pill and kick started myself into some seriously unhealthy habits. I got perfectly thin. But I also got seriously dependent. I felt so happy when I took it -- a false sense of well-being that made me downright foolish. I felt like nothing could hurt me...but the drug (and it is a DRUG honey) became like a deep need. My heart suffered, my personal life suffered, my health deteriorated. I'm guessing you're reading this and thinking it won't happen to you...well hear this -- I have never done any kind of drug. Never been dependent on alcohol or anything. I was a public school teacher, and ADDICTED to this thing. When people who love me begged me to get off I finally did and had terrible dizzy spells, fatigue that required me to lay down, and I gained weight. You will too. My husband made me promise to never touch the stuff again. Honestly, I don't know why it's legal when so many people get strung out on it and have heart attacks...and I wonder if they' husll even print this review. Danger people. Run away.

posted Jul 11th, 2011 11:44 pm

Miss Nell


I was a Pink Lady in a hospital in Alabama back in the 80's. I noticed a lot of staff was losing weight like crazy so I asked one what was going on. She said that they were taking Fastin capsules.

I asked my doctor, (staff also) if he would give me a Rx, he said "sure" and pulled a Rx pad from his pocket and gave me one for 1 month's supply, (with a verbal refusal for more, due to addiction possibility).

I had the prescription filled for $2.49 and took one the next morning... Life was GOOD!

I totally forgot about food! I cooked for my family, and ate what I wanted, I just didn't want food! Not even foods that I loved and salivated when I smelled them. I found out on the third day that I could skip a pill and not know the difference. I lost 30 lbs in two months because I stretched the pills out to one every two and sometimes three days. I OWNED MY WORLD! I had no problem sleeping; no shakes, no headaches, NOTHING!

I have pined for Fastin all these years since, like an old love! I knew they had been pulled from the market, and I had moved away from Alabama, but I will never forget my affair with Fastin. I'm 67 years old now and fat. I can't bring myself to ask my young whippersnapper doctor if I have another go with Fastin. I'm diabetic now and don't want to kick-out and leave my grandchildren because of a few pounds!

posted Jul 1st, 2011 7:25 pm


Leave Feedback

Or, proceed without an account


Already a member?

Whats better than