FENFAST 375 Rapid Fat Burner Review

fenfast 375 reviewIn my opinion, one should avoid any product that makes claims that sound to good to be true. The word “rapid” in the name “Fenfast 375: Rapid Fat Burner” sets my bull sh*t alarm off every time. But that being said, here at supplementHQ we strive to provide complete, unbiased reviews, regardless of personal word biases.

Weight loss supplements are the most sold AND the most controversial segment of the supplement industry. When people think of scammy products, weight loss supplements is the first thing that comes to mind. I personally think that this mindset is unfair. It has nothing to do with the science behind these products, and everything to do with dishonest marketing that is the norm in the weight loss industry. Our goal is to weed through the BS and find, rank, and review the BEST products in the world.

When shopping for supplements, focus on the ingredients, the science, and the studies (if available) when making your decisions. You will be leagues ahead of the average and your results will show.

Product Claim Review

The product claims are pretty far fetched and dreamy eyed. Again, know your science, know your ingredients, and know what to expect.


Fenfast 375 claims to cut calories as much as 50% a day. Seeing as it is primarily a thermogenic supplement, I imagine they mean that it will burn 50% of your daily caloric intake. Still an insane claim.

Pharmaceutical grade means that the product is 99% pure and has no fillers, binders, or dyes. Seeing as it is a tablet which requires binders, I find this to be unlikely. Also the blue dots are almost certainly dye. This claim disappoints and makes me lose trust in the product.

Fenfast 375 also claims that it boosts energy and suppresses appetite. After reviewing the ingredients (see below), I think this claim checks and is approved. Fenfast should definitely increase energy as caffeine and Hordenine are 2 primary ingredients.

Last of it’s claims is lose 15-25 pounds a month. Oh my oh my. This is the mother of all claims and is complete and udder bull sh*t. There are no magic pills that will make you lose 15-25 pounds per month alone. Fenfast is a powerful thermogenic, but boosting your metabolism is all that you can expect. Yes this can increase the amount of calories you burn, but if all things are constant except the addition of Fenfast, you will not lose that much weight. All things consistant, 2lbs at best… in my opinion.

How it Works

Fenfast 375 works as a central nervous system stimulant. This essentially increases your energy by making your body work harder. Harder work = increased calorie burning. The fewer calories you consume, the less of those calories will turn to fat. If your diet is right, and you also work out (lift weights, cardio exercises, etc), than eventually your body will run out of calories from food, and turn to calories from fat. When this happens, you are burning fat and losing weight. Hallelujah!

If your fitness and eating habbits are were they should be, a thermogenic like Fenfast can help in your weight loss efforts. But is Fenfast THE BEST? Keep reading and we will get into it.

Also, remember that increased energy from stimulants will also increase your fatigue later. AKA the crash. Make sure to get proper post workout nutrition as well.

Personal Results

I tested Fenfast 375 for a month, taking 4 tablets a day. I honestly felt pretty dang good on the product. More alert, more focused, and just overall in a good mood. There’s no doubt that this is a product you can feel. HOWEVER, I kept all other aspects of my live as consistent as possible (including fitness, diet, and sleep). The results… 1.25 pounds heavier.

Now who knows, the extra energy could have made me workout harder – although I made an effort to stick to my normal routine. It is possible that I decreased body fat and increased muscle. Unfortunately, I did not monitor my body fat percentage. I did notice an increase in blooding and my poop schedule was thrown off big time… but that’s just me.

Overall, I personally found that I respond better to other products, similar to the ones found here – mostly because those don’t mess with my digestive system.

Customer Reviews

reviews from amazonOutside customer reviews is a very difficult category to judge. Places like Amazon are jammed packed with fake reviews. In fact, there are companies (most of them located overseas) that will sell fake amazon reviews for about $3-15 per review. And yes, even “verified” reviews.

What I found interesting/suspicious about Fenfast is that they have hundreds of great reviews, however, when you switch from most popular (a sorting feature easily manipulated) to most recent, the reviews suddenly switch from all 4’s and 5’s, to all 1’s and 2’s. Not a good sign.

Also, I wasn’t able to find any good or even slightly positive reviews on reddit or other forums. My suggestion, stick with a product that is well regarded on supplement review blogs or by fitness experts. Also, learn the science behind them and know the ingredients.

Ingredient Profile Analysis

Fenfast 375 actually has some ingredients I like to see in a fat burner. However, I’d love to see MORE from this product. It is a great stimulant, but that is about it.

The ingredients are as followed…

Beta Phenylethylamine HCl: Phenylethylamine is a very common fat burner and mood enhancer. It effects the neurotransmitter dopamine – which is responsible for making you feel good. It is derived from chocolate. This effect on mood ultimately positively impacts focus, after the initial mood boost wears off. Phenylethylamine pairs well with hordenine.

Caffeine Anhydrous: The most popular supplement in the world. Caffeine is a central nervous system stimulant that increases energy and metabolism resulting in increased caloric burn.

Hordenine HCl: Works by releasing norepinephrine – a hormone that energizes the body fueled ultimately by fat.

L-Theanine: L-Theanine is great, especially paired with caffeine. Both caffeine and l-theanine are found naturally within green tea. Studies have showed that when paired together, they offer a more level energy boost and more balanced weight loss. Personally, with caffeine alone I feel anxious. But when paired with L-theanine, I feel a reduction in fatigue and increased motivation.

Company Analysis

Finding a copy of the supplement facts panel was very difficult. I lose a lot of trust in a company when they are not transparent about their ingredients.

Fenfast tries to look like prescription medication. Creative and sneaky marketing doesn’t reflect on the effectiveness of the product (which is ultimately all we care about), but it does make me look down on the company. The fact is, this product is a supplement and only contains supplemental ingredients. It is not prescription medication.

Neither the website or amazon seem to advertise a review, however, if you are unsatisfied, amazon will grant refunds in the buyers defense.

Alternative Options

Fenfast has created a decent stimulant based product that will work as a thermogenic. However, there are many fat burning/thermogenic products that have substantially better science behind them.

Here are a few of our top ranked fat burners, in order of our team’s favorites:

  1. Thermakor by Kor Nutrition
  2. Hydroxycut
  3. BSN Hyper Shred

– Read the full review here.


All company sleaziness and dishonest marketing aside, Fenfast 375 would actually make a decent thermogenic.

Thermogenics, fat burners, and weight loss supplements are commonly used as synonymous terms, but thermogenics specifically refer to increased metabolism and calorie burning. Do not expect insulin control, fat cell regulation, appetite or digestive aid or anything else. This is just a stimulant. 

If you are looking for a good stimulant to energize your workouts and burn a few additional calories a day, then Fenfast 375 might just be the product for you.

However, we recommend checking out our ranking for the best thermogenic fat burner supplements. Many of our top ranked thermogenics contain additional ingredients (besides just stimulants), that work to not only boost metabolism, but also to prohibit new fat uptake and regulate insulin responses within the body.

$49.50 for a stimulant is way over priced.

Where to Buy

We recommend buying from Amazon as the Fenfast website doesn’t look very trustworthy.

Click here to buy from Amazon. 

As mentioned above, amazon also has more buyer protection, so if you are unsatisfied, you can get refunded, even if the seller doesn’t offer it.

About SupplementHQ

SupplementHQ is the leading review site for supplements. With a focus on ingredients and the clinical studies that support them, SupplementHQ works to cut through marketing hype and bring to light the most effective, science-backed products available on the market. Connect with us on facebook, twitter, or email for supplement giveaways and coupons!


  1. Fenfast suckkkkks. Stick to the basics. This one is way over hyped.

  2. Not our favorite either. Is there any weight loss products that you have used and found successful? Or is there any that you would like us to review before buying? Please let us know!

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