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What Is Phen375 And Does It Actually Work? [A Review]

what is phen375

In a nutshell, Phen375 is an over-the-counter dietary supplement designed to help you reduce your appetite and burn more fat naturally. Yeah, I know- there’s a lot going on in that statement (don’t worry, we’ll dive into the specifics below).

If you’ve been in the market for these supplements for awhile, you may have come across Phen375 because it’s been around for some time. In a world where fad products come and go at an alarming rate, this might say something for this product’s merit… then again, it may not.

It’s hard to come up with a definitive answer to whether or not a weight loss supplement is effective. User reviews are too subjective because everyone has their own experience with their own conditions (diet, workouts, age/weight/fitness level)- simply put, too many variables.

The best way I know to go about reviewing a product like this is to dive into the ingredients- does it make sense that this combination will help do what the company behind it is saying it will do?

My goal for this review is to provide you an in-depth discussion of the science (or lack there of) behind this supplement so you can make an educated decision on whether or not it’s worth trying.

Let’s dive right in.

What Is Phen375?

The dietary supplement market is massive (estimated to be worth over 100 billion dollars last year) and there are a ton of products out there designed to help folks lose weight.

Phen375 is one of these supplements.

The “phen” part of the name is referring to phentermine– a weight loss drug often prescribed for folks that are having a hard time losing weight with diet and exercise alone.

Actual phentermine is an upper (much like amphetamine) and can only be used for short periods due to the long list of possible side-effects.

Phen375, like many weight-loss supplements, claim to use “natural” phentermine- safer ingredients that can provide the same appetite suppressing benefits of phentermine (without all the risk).

Some supplements are better than others obviously. If you’re looking for a something to help you along your weight loss journey, the key is to try and find one that can offer some type of benefit.

Phen375 claims that it can help you lose weight by reducing your appetite and increasing your metabolism. Either task would be daunting enough on its own, but this pill attempts to achieve both.

This supplement has been on the market since 2009- this means that whether it actually works or not, people are definitely buying it.

If they weren’t, it would’ve disappeared a long time ago.

That said, this company currently has an ‘F’ rating with the Better Business Bureau (BBB). This is based on the complaints they’ve received about Phen375’s customer service.

Most of these complaints are regarding difficulty returning products or from people having a hard time reaching customer service to begin with. Some where also disputes over charges folks say they didn’t ok.

The fact that Phen375 has been around for so long is a good sign, but the user reviews are all over the place. Which I must say, is pretty common for weight loss supplements.

It just goes back to what I mentioned at the beginning- there are too many subjective variables. Everyone has their own expectations too. If I’m looking for a pill that will make me lose 5 lb a week and Phen375 isn’t able to deliver, I’m going to be disappointed.

Unrealistic expectations and unknown conditions make it hard to go by user reviews on products like this.

It would be great if the company or an outside party performed a research study to determine the effectiveness of a supplement like this. You know what I’m talking about: a control group taking a placebo compared to another group of similarly aged folks who were given the supplement (with everyone performing the same exercise plan and eating the same diet).

This would be the gold standard for determine a supplements effectiveness.

Unfortunately this type of research doesn’t exist for Phen375 (or really any supplement for that manner).

Instead, we have to look at the ingredients and see what benefits they can offer.

Phen375 Ingredients

Here’s a list of the ingredients that make up Phen375, along with an explanation of what each is supposed to provide in terms of weight loss:


L-carnitine is an amin0-acid that is found naturally in our bodies. It’s used for energy production and plays an important role in many bodily functions.

L-carnitine supplements are used to treat several disorders and have been found to be effective in treating kidney disease (for people on dialysis) and for genetic disorders causing L-carnitine deficiencies (go figure).

Although some studies have shown that this amino-acid can help with weight loss, it seems to be most effective when used in combination with other drugs and when used by people with diabetes.

Other research shows that L-carnitine isn’t effective for weight loss when used by healthy individuals, even when combined with exercise.

According to the research, it’s doubtful L-carnitine will do much to help health individuals lose weight

Caffeine Powder Anhydrous

This is basically a form of caffeine (powder form, anhydrous means without water). Caffeine is often used in weight loss supplements because it is known to increase metabolism.

It also gives you a nice jolt of energy, making it easier to get a good workout in.

A lot of research has been done on caffeine and exercise performance, and the general consensus is that caffeine can definitely help you perform better athletically as well as lose more weight.

Caffeine is one of the most popular weigh loss supplement ingredients and has been well documented in it’s positive effect on weight loss

Coleus Forskohlii Root (Forskolin)

Forskolin is a chemical found in the root of the coleus forskohlii plant- a tropical version of mint. It’s been used for years to treat all kinds of health problems and is still used today primarily for heart disorders and asthma.

Over the last few years, it’s also become a popular ingredient in weight loss supplements, after making an appearance on the Dr. Oz show.

The idea is that forskolin helps the body release stored fat from fat cells. As this happens, your body uses the fat for energy and your fat supply decreases.

There have been a couple of small studies that have looked at the effect of forskolin on weight loss in obese individuals. The results are fairly promising, with one study showing a significant decrease in body fat (although no significant change in total weight) through the use of this supplement.

Based on early research, forskolin may be useful in losing body fat, but not necessarily reducing your total body weight. The research is still limited at this point though.

Citrus Aurantium

Also known as bitter orange, this ingredient is often found in weight loss supplements for its possible effect on appetite and metabolism. Bitter orange contains synephrine, which has been shown to increase metabolism and possibly help lower appetite.

Like most of these ingredients the research is fairly limited.

Citrus Aurantium, or bitter orange, contains compounds that have been shown to increase fat burning and metabolism, but like most of these ingredients, the research is pretty unclear.

Cayenne Pepper

We’re all probably familiar with these spicy peppers, but it’s actually the capsaicin in these peppers that are likely responsible for all the health benefits.

Studies have shown that taking capsaicin supplements can help boost metabolism, which leads to burning more calories. Capsaicin has also been shown to decrease appetite and make you feel fuller, longer.

Cayenne pepper contains capsaicin, which has been shown to increase metabolism. It might also play a role in curbing your appetite. It’s also a very safe ingredient with very few side effects.

Calcium Carbonate

Calcium carbonate is the chalky stuff used to treat indigestion and heart burn. It reduces the amount of acid in our stomachs, providing relief from the above gastrointestinal issues.

This ingredient doesn’t play a strong role in weight loss, although some research suggests that diets higher in calcium are more likely to help you sustain healthier weights.

This ingredient is likely included to help keep your stomach happy as it digests everything else in Phen375.


Chromium is an element that has been shown to aid in controlling blood glucose levels. It’s also gained some popularity as a weight loss supplement, although research doesn’t seem to back it.

According to this study, chromium supplementation had no significant effect on weight loss. Other studies seem to find the same result.

Chromium doesn’t appear to have any direct effect on weight loss.

Dendrobium Nobile Extract

This is the extract of a certain type of orchid plant. It’s been used in traditional Chinese medicine for years, but has recently become a popular ingredient in workout and weight loss supplements.

There isn’t much research on its effect on weight loss, but it seems to have chemicals in it that act as stimulants. Before it was added to diet pills, it was used to treat all kinds of ailments like fever, infection, and inflammation.

There’s really no research looking into the effect of this ingredient on weight loss, although it has been used for centuries in ancient Chinese medicine.

So, based on the research, the following Phen375 ingredients have been shown to be effective for improving metabolism or helping with appetite control:

  • Caffeine powder
  • Forskolin (losing fat)
  • Citrus aurantium
  • Cayenne pepper

That’s 4/8, or 50% of the ingredients.

The other 4 have very little research or research showing that they are ineffective for use in weight loss.

How To Use Phen375

This might sound silly, but I’m being serious. The folks behind Phen375 have set up a very standardized program to ensure the best results.

And it’s not as simple as just taking their supplement and going on with your day.

I should mention that Phen375 offers a 60-day money back guarantee if you’re not satisfied with your weight loss. BUT, in order to qualify for that refund, you have to follow their directions EXACTLY as they state it.

To use this supplement correctly (according to, you must:

  • Download their free diet plan and select the option that best describes your situation
  • Record your starting weight before you begin
  • Follow said diet plan for 30 days while recording your progress along the way
  • Record your final weight after 30 days of following the diet plan (and taking Phen375)
  • If you haven’t lost any weight, you have to send them a written sworn statement as proof that you followed their diet plan and you still didn’t lose weight

On top of the meal plan, they encourage you to drink more water and exercise regularly.

Part of me thinks it’s silly to have to jump through all these hoops to get a refund. What happened to “the customer is always right”? If they didn’t see the results they wanted, why not just let them send it back and give them the refund?

The other part of me likes that Phen375 is forcing users to follow a diet plan.

This shows us that the producers of this product are admitting that this isn’t a magic weight loss pill.

And that’s the truth. Unfortunately, there is no magic pill that can make you lose weight without decreasing your calorie intake.

I’m old school. There’s only 2 ways to lose weight: eat fewer calories than you’re burning, or burn more calories than you’re eating.

And Phen375 doesn’t seem to disagree.

They are basically saying that their supplement is designed to help you curb the cravings while you’re following a healthy diet. A healthy diet that will probably be about 500 calories less than your normal diet.

Of course, the truth is, you should lose weight without any supplementation if you are cutting 500 calories out of your normal diet.

Again, Phen375 admits this too.

They make it pretty clear on their website that this supplement is designed to help you feel fuller while you lose weight the old fashioned way.

And if you’ve ever tried good ol’ fashioned dieting, you know how tough it is. If Phen375 can actually help you decrease your appetite, it may be worth the price.

But Does Phen375 Work?

Ah, the million dollar question. This is what you really want to know if you’re reading this review. Does it actually help people lose weight?

Well, according to the users…sometimes.

That is, user reviews are all over the place. Some people noticed a decrease in their appetite, others didn’t notice anything at all. Some folks also reported feeling more energetic while using this supplement, others didn’t.

Based on user reviews alone, it’s really hard to say. For every good review, there’s an equally negative one.

But as I’ve mentioned a couple times now, it’s difficult to go by these user reviews because everyones situations and expectations are different.

Did the people who gave it negative reviews not lose weight because they didn’t follow the reduced calorie diet or did the pill really not help with appetite control? Who knows.

The same goes with the positive reviews.

When we look at what Phen375 is made of, we see some ingredients that have been shown through research to increase metabolism. We see others that don’t seem to have any affect on weight loss at all.

I can see how this supplement could help increase energy levels due to the caffeine it contains.

Another thing I want to point out here, is that the list of ingredients is actually pretty small. We don’t see a laundry list of chemicals jammed in this pill to try and help with weight loss by any means possible.

Everything ingredient in this supplement is from a natural source. I like that.

Overall, based on the ingredient list and the research I’ve done on Phen375, the best I can come up with is that this supplement is probably capable of helping some folks reach their weight loss goals.

Will it work for everyone?- nope.

Something else that is evident to me- if you follow their nutrition plan, you should lose weight with or without the supplement.

Purchasing Phen375

If this supplement sounds like something you’d like to try, you can only buy it directly through their website,

Buying in bulk decreases the price per bottle, but you can purchase single bottles as well. A single bottle will cost roughly $65, depending on what special that is currently running.

Compared to other similar products, this asking price looks fairly average. Some are pricier, others cheaper.

Keep in mind you have to try it for a full 30-days to be eligible for the money-back guarantee.

Phen375 also states that “average” results are losing 5-10 lb per month, which is actually pretty reasonable considering you should expect to lose 1-2 lb/wk with a 500 calorie/day deficit.

Final Thoughts

Phen375 is a dietary supplement designed to help you lose weight by reducing your appetite and increasing your metabolism. In a market saturated with weight loss supplements, it’s kind of impressive they’ve found a way to survive for over 10 years.

Of the 8 natural ingredients in this supplement, 4 have research supporting their merit in aiding with weight loss. The others not so much.

My biggest concern with this supplement is the poor customer service reputation. An ‘F’ rating by the BBB – ouch.

If you’re serious and follow their nutrition plan, I think most people should lose weight with or without the supplement (you can check it out for free on their website- nothing too fancy, just healthy meals, high on lean protein and low on processed foods and carbs).

But the truth is, following this type of nutrition plan is really hard. It takes a lot of discipline. And this is why most people fail.

If Phen375 can make following a healthy diet more doable, then it may be worth trying. But please don’t expect miracles- Phen375 is only designed to make following a diet more doable. You still have to eat less and move more!

Lose Weight with Phen375





Will's a licensed physical therapist (DPT) with over 15 years of experience treating patients from all backgrounds. He's been lifting weights and exercising in one form or another since middle school and has been working out in his own home gym for over a decade. When it comes to fitness equipment, there isn't much he hasn't tried. In his spare time, if he isn't writing or working out, he's likely playing basketball, watching movies, or hanging with his family.

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