Updated 7th August 2023
Phenaprin is a dietary supplement marketed as an OTC phentermine alternative. Phentermine diet pills are known to greatly aid your weight loss efforts, but cause a host of side effects. Phentermine alternatives like Phenaprin have become popular as they claim to offer all of the health benefits with none of the drawbacks.
Phenaprin claims it can support weight loss, productivity, and mood, burn more calories, aid your wellbeing, control appetite and food cravings, and boost metabolism and energy levels, to help you hit your goals. Unfortunately, our analysis of the product found the claims regarding Phenaprin diet pills just are not true.
The Phenaprin diet pill formula consists of a proprietary blend of l-phenylalanine, theobromine, caffeine anhydrous, l-taurine, l-carnitine, and DHEA. Having everything lumped into a proprietary blend is always a red flag, as they are often used to hide low ingredient dosages in a poor quality supplement.
Luckily, based on the weight of the blend and the placement of the ingredients in it, we were able to determine that this is exactly what they are doing, as the proven ingredients are all present in dosages that are far too low and then surrounded by others that need more evidence to prove they aid weight loss.
It then also features a range of other ingredients that includes dicalcium phosphate, microcrystalline cellulose, stearic acid, sugar, croscarmellose sodium, magnesium stearate, silicon dioxide, corn starch, and fd & c blue number 1.
While none of these offer any beneficial effects in a weight loss dietary supplement and are only included to improve things like its taste and texture, you do have the potential to cause side effects and take up space that could have been used for active ingredients.
You put all of this together, and these diet pills aren't just unsuitable to be used as prescription medication or phentermine alternatives, but they are unlikely to benefit your weight loss goals in general.
That is why we recommend you do not buy Phenaprin and stick to wait loss aids that actually contain functional ingredients in their correct dosages.
Customer reviews of Phenaprin weight loss supplement are fairly underwhelming, and the diet pills hold an average rating of 3.4 out of 5 stars with past users on Phenaprin's Amazon.
When looking at reviews that gave it 4 or 5 stars, people did say that they found it could increase energy levels quite well and some even felt that it prevented them from storing as much body fat.
However, even many reviewers who gave it 5 stars said that they did not find it helped them to lose weight any faster, which is far from ideal in a weight loss supplement. In fact this, very much looks like most people were offered a refund to upgrade their review to 5*.
What's more, there was no mention of any appetite suppression, which means it can't possibly be used as an alternative to phentermine hydrochloride like the manufacturers suggest. Although some people did specifically mention it helping with cravings.
When you get to the negative phenaprin reviews that gave it 1 or 2 out of 5 stars, things then quickly go from bad to worse.
From people saying that it did not promote weight loss or help with burning fat in any way, to users who experienced severe side effects like anxiety, depression, mood swings, stomach pain, heart palpitations, feeling light headed, and numbness in the extremities, it was just one issue after another.
This only goes to further our belief that you should not risk your health or money on the Phenaprin weight loss pill.
At the time of writing there are no Phenaprin reviews on trustpilot, however we did find a few reddit reviews of Phenaprin, that are definitely not placed by the brand themselves.
Phenaprin reviews from reddit largely complained about the product being a scam or that the product itself could in fact be dangerous.
There were more than a couple of people asking similar questions on whether or not Phenaprin could help and the vast majority of responses were negative. Although it should be mentioned many of the comments had not tried the pill. many of these users took the same issues that we do with the product as a whole.
Phenaprin is a proprietary blend of 540 MG, meaning the exact ingredient volumes can vary and they won't be completely consistent across all batches. It does also mean that legally ingredients have to be listed from largest to smallest, and this is the most consistency that is required when producing supplements like this. And that fact allows us to work out approximately how much of each ingredient is likely to be present, although in many cases you would need more than the entire blend for the ingredients to be within their effective dosages so it doesn't always matter too much.
L-Phenylalanine - Phenylalanine is an essential amino acid that is widely found naturally in meat and eggs, as well as nuts, beans, dairy products, and even sweet potatoes. It is usually put in a human dietary supplement as there is a large amount of evidence to suggest that it can be used to treat a skin condition known as vitiligo.
However, it is beginning to be put in numerous other dietary and weight loss supplements too, due to claims that it can be used to promote weight loss, treat depression, relieve the symptoms of ADHD and chronic pain, slow the signs of aging, and offer a host of other health benefits.
Unfortunately, with the exception of its benefits for sufferers of vitiligo, there is little to no evidence to support any of these claims. Worse still, it has also been linked to an extensive range of severe side effects, such as anxiety, constipation, headaches, seizures, brain damage, and other mental problems (1).
Given that they do not even tell you how much l-phenylalanine is present in a serving of Phenaprin diet pills, we can't be sure, but 250mg is the recommended dosage, meaning that as the first listed ingredient it's likely in the correct dose, bu tthis means that nothing else in the pill is likely to be.
Theobromine - Theobromine is an insoluble isomer and alkaloid found in cocoa beans and is what gives dark chocolate and cocoa their bitter flavour. It produces a stimulating effect similar to that of caffeine, but is used far less frequently as it is not as potent, although it does have a notably longer half life.
Theobromine can provide a number of beneficial effects that can aid you while you are losing weight, such as to give you an energy boost and suppress appetite, and it can even reduce bloating and inflammation, improve your mood, and keep your mind and body healthy at every stage of your weight loss journey.
The issue is, theobromine is only really a weight loss aid when you take at least 500 mg each day (2). As the second ingredient listed in a proprietary blend that weighs just 540 mg in its entirety, Phenaprin diet pills therefore simply cannot contain enough theobromine for it to be capable of producing these effects.
Caffeine Anhydrous - Caffeine is one of the most popular and powerful stimulants on Earth and is consumed in everything from tea and coffee to energy drinks and dietary supplements. Caffeine anhydrous is simply a concentrated and dehydrated form of this stimulant, which is considerably stronger.
Caffeine is put in a dietary supplement for weight loss like this as it can give you more energy to do harder, longer workouts, stimulate lipolysis and thermogenesis to promote excess body fat burning directly, reduce fatigue to help you train more and recover faster, and improve your brain functions and mental focus.
The problem is, in order for these effects to occur, you must consume at least 200 mg of caffeine a day (3).
The proprietary blend that the Phenaprin weight loss supplement uses admittedly does a fairly good job of trying to hide the amount of caffeine anhydrous that it contains. However, given the weight of the blend and its place on the ingredients list, we can still easily work out that it does not contain a sufficient dose.
L-Taurine - Taurine is an amino acid usually found in red meat, poultry, seafood, eggs, dairy, and some seaweeds. It is essential to help the human body maintain the optimal health and functions of the brain, eyes, heart, nerves, and skeletal muscles, and it can also help to lower your "bad" ldl cholesterol levels.
It is also commonly found in many commercial energy drinks and pre workout, fat burner, and weight loss supplements, as it can significantly increase energy levels and accelerate stored fat loss.
However, taurine will only produce these effects if you consume at least 3 grams a day. Given the fact that this is more than 5 and a half times the weight of the entire blend that it is listed in, it is therefore simply not possible for Phenaprin weight loss pills to contain enough to be of any use (4).
L-Carnitine (As L-Carnitine Tartrate) - L-carnitine is an amino acid derivative that is most prominent in red meat, but which can also be found in fish, poultry, and dairy. It is sometimes put in weight loss supplements as it can improve the body's ability to burn fat cells and increase metabolism of fatty acids.
The idea is that, not only would this release fat burning hormones to promote weight loss directly, but it would also give you so much energy that completing extremely long and intense workouts would become much easier, leading to even greater weight loss success.
It can even offer other health benefits too, like boosting brain and heart health and functions, regulating blood sugar, blood pressure, blood lipid, and insulin levels, reducing inflammation and oxidative stress and damage, and treating type II diabetes, liver disease, metabolic disease, depression, and some other issues.
Unfortunately, there a couple of issues with the use of l-carnitine in a weight loss pill. Not only is more evidence needed to confirm how well it can burn fat cells, but side effects like gastrointestinal discomfort, narrowing of the carotid arteries, and the development of a "fishy" smell have all been reported (5).
What's more, at least 500 mg must be consumed each day for l-carnitine to do you any good what so ever, which is far more than can possibly be present here. This means the l-carnitine content of the Phenaprin weight loss pills is all but guaranteed to do you no good at all.
DHEA (Dehydroepiandrosterone) - DHEA is a hormone produced by the adrenal glands of all humans. Primarily responsible for stimulating the production of the sex hormones oestrogen and testosterone, it can also promote optimal bone and heart health, improve your endurance, and help to prevent depression, sexual dysfunction, and the signs of aging.
While not a common ingredient in diet pills, daily doses have been shown to aid with body weight management, insulin sensitivity, body fat storage, mood, exercise performance, and the treatment of certain diseases that could lead to weight gain (6).
However, not only is more research needed to help us fully understand all of the effects of DHEA, but studies also show that doses of around 200 mg per day must be taken for it to be effective. As Phenaprin diet pills can't possibly contain this amount, its inclusion in the supplement is absolutely pointless.
Other Ingredients - The other ingredients listed on the Phenaprin weight loss supplement are dicalcium phosphate, microcrystalline cellulose, stearic acid, sugar, croscarmellose sodium, magnesium stearate, silicon dioxide, corn starch, and fd & c blue number 1.
None of these will add any beneficial effects to a natural appetite suppressant, fat burner, or weight loss supplement, but they may still cause side effects and take up space that would have been better served on increasing the dosage of the active ingredients.
Contains a number of ingredients that are proven to help people lose weight
Does not contain a single proven weight loss aid that is present in its required dosage
Some of the ingredients need more research to prove how much they will aid body weight loss
Customers have complained about both a lack of efficacy and experiencing an extensive list of severe side effects
Does not provide anywhere near the level of fat loss or appetite suppression you would expect from a diet pill marketed as a phentermine alternative
1 - https://www.ncbi.nlm.nih.gov/books/NBK482165/
2 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3672386/
3 - https://pubmed.ncbi.nlm.nih.gov/30335479/
4 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5933890/
5 - https://examine.com/supplements/carnitine/
6 - https://pubmed.ncbi.nlm.nih.gov/25022952/