Updated: 09/29/2015 - Sponsored by Leptigen

PhenTabz Review - Does This Fat Burner Work? Are ingredients and side effects deal breakers?

Editor's Review: 3.5 / 5.0

phentabz-product-imageThere’s quite a buzz about Phentabz, so we dug deep into the ingredients, side effects, scientific research and customer service. Additionally, we jumped into hundreds of consumer comments and reviews. We then condensed and summarized to give you the info you need.

EDITOR'S TIP: Substitute PhenTabz with a proven fat burner such as Leptigen for better results.

What You Need to Know

First off, Phentabz is a fat burner containing caffeine, DMAA and synepherine. The recommended dose is one capsule per day, not to exceed two capsules and this supposedly assists with weight-loss. One benefit of the capsule is ease of use.

The product was introduced in 2001 by Gentech Pharmaceuticals. The company also sells the supplement under the banner of Lexium International. You can purchase it on the official website, but we couldn’t find it available anywhere else. We do like that the company has been in business for more than 10 years, but read on…

Ingredients Unsafe – “FDA Says Yes!”

The first concern for us was Phentabz ingredients. “Caffeine is considered a safe and effective weight-loss supplement,” said our Research Editor. “But, when a diet pill contains a banned substance like DMAA, there could be an issue.”

According to the FDA, “DMAA, especially in combination with other ingredients such as caffeine, can be a health risk to consumers. Ingestion of DMAA can elevate blood pressure and lead to cardiovascular problems ranging from shortness of breath and tightening in the chest.”

It’s also important to note, “DMAA-containing dietary supplements are illegal and their marketing violates the law. Based on the scientific information reviewed by FDA, DMAA is not a dietary ingredient.”

Scroll below for one of the best products we’ve seen in 2015.

Side Effects – A Major Concern

Based upon several customer comments, Phentabz side effects are severe. “I have not experienced weight loss yet, but there are side effects like feeling edgy and jittery and going to sleep at night has been difficult,” said a consumer.

“The only side effect was that it was making me jittery,” offered a dieter.

“I get these hot sweaty episodes with a heavy weight feeling on my chest, and it gets hard to breathe,” reported a user.

Our research shows that if an issue arises, like side effects, this could hinder long-term success. If Phentabz does in fact cause adverse reactions, there is a problem.

The Science

While the official Phentabz website makes the case that the supplement is an effective weight-loss pill, we can’t find any clinical studies, speaking directly to the benefits of the ingredients. We did locate several cases where the Food and Drug Administration has banned DMAA from products. At DietSpotlight, finding science to back claims is critical. If there is no research, dieters should probably walk away.

The Bottom Line

After a comprehensive look at Phentabz, we’ve reached a decision. There are some favorable aspects of the product, like the longevity of the parent company and some positive customer comments, but we can’t recommend it because of the lack of clinical research supporting weight-loss claims. Plus, we’re concerned about the combination of ingredients and the “F” Better Business Bureau rating.

If you’d like to see real results, we recommend going with a product that doesn’t put a dent in your wallet and contains ingredients backed by published clinical research.

Among the best products we’ve seen in 2015 is one called Leptigen. The supplement contains a four-ingredient proprietary blend, shown in published scientific research to help enhance fat loss and ignite metabolism. There’s no talk of negative side effects and customer reviews state people are seeing exceptional results.

Also, the makers of Leptigen are confident in the supplement, so they’re offering a special trial offer, which is an excellent choice.

Learn More About Leptigen »

(Feel free to scroll below for our previously published full-length PhenTabz Review)

Previous PhenTabz Review (Updated February 6, 2014):

What You Should Know

Click Here To See Our Highest Rated Review

PhenTabz is a weight loss supplement that claims the only side effects from taking the supplement are increased energy and faster weight loss. The official website looks like a website for a prescription drug, which is exactly what the company is going for. According to the PhenTabz description, the supplement works like Phentermine, the prescription weight loss drug, but dieters don’t need a prescription. There are three products described on the website: PhenTabz, PhenTabz Teen and PhenTabz RX. None of these products lists ingredients used to promote weight loss.

List of Ingredients

  • None listed.

Product Description

We looked through every link on the PhenTabz website and not one ingredient is listed for any of the three formulas Gentech Pharmaceuticals wants dieters to trust. There is mention of a proprietary blend in the FAQs section of the website, but the ingredients present in that blend are not listed. Weight loss supplement companies have a responsibility to list all ingredients so dieters can review ingredients and choose whether or not they want to try a product. Moreover, some natural ingredients are contra-indicated when prescription medications are taken. Gentech Pharmaceuticals expects the dieter to just choose PhenTabz on faith that none of the ingredients cause negative side effects and that’s not a responsible choice for dieters to make. The blatant use of medical images and the extension “RX” is something we consistently tell dieters to avoid. Diet supplements are not medical supplements. Prescription medications are reviewed and approved by the Food and Drug Administration. The same cannot be said for weight loss supplements. We are also concerned that Gentech Pharmaceuticals markets a diet supplement for teens. Ingredients commonly used in diet supplements are not tested on teens and thus should not be considered healthy or safe for teen consumption. Of course, we are assuming there are ingredients other than those found in common vitamin supplements because the company does not list ingredients.

See Our Featured Diet


  • PhenTabz can be purchased online.


  • No ingredients are listed for any of the PhenTabz products.
  • The marketing push is clearly toward dieters looking for phentermine without a prescription.
  • There is a product aimed at teens.


The first thing we look for when reviewing a diet supplement is an ingredient list. If a company is not willing to reveal the ingredients used in the formula, they are not willing to earn the trust of the consumer. We can only assume Gentech Pharmaceuticals is hiding something by not publishing the complete list of ingredients for PhenTabz, PhenTabz RX and PhenTabz Teen.
GD Star Rating

11 User Reviews About PhenTabz

Leave comments below
  • 1
    So Disappointed

    This product was the biggest waste of money! I saw the advertisement for PhenTabz in my Dr’s office so of course I thought it was credible. I was so disappointed. Can’t wait to my next Dr’s appointment to tell them that they are advertising a garbage product! There was absolutely no “dry mouth” or any other alleged “side-effects” because it’s a placebo product formulated by a company that is preying on people struggling to lose weight!


  • 2
    Patricia thomas powell

    I would like to ask if I could take this if I am on the kidney machin three times a day.


  • 3

    I have PhenTabz and the ingredients is clearly stated in the bottle’s label. It say Proprietary Formulation consisting of 7-methyltheophylline, Methyl Synephrine HCL, and Octopamine.I have not started them yet. I will repost when I do.


  • 4
    arabella shah

    I can not sleep when I take it


  • 5

    yes it works! i have lost weight on it and i do like it. at first it makes me quiet and i work all day. after i get use to it, its fine. i was gettting from a doctor but office vists and such but i found it here. i havent ordered it yet from online but i do know that i have had success with it with really no side effets.


  • 6

    This product sounds great.But I just can’t try this without knowing the ingredients,that’s so risky what if there’s something in it that I’m allergic to.I just can’t be faithful on them,and I guess if they don’t want to reveal the ingredients soon I’ll have to look else where to find supplement that will help me loose weight.


    Your Name

    I posted the ingredients! Hope it helps


  • 7
    mom of 3

    Their flyer lists these ingredients:
    “Patented Ingredients”: 7-methyltheophylline, Methyl Synephrine, & Octopamine.


  • 8
    safa saleh

    I am 17 years old this product does seem that it works but does it really keep the weight off? and would I get high blood pressure or anything like that after the weight is gone?


  • 9

    Is the a problem taking PhenTabz with zoloft?


    Your Name

    Is aproblem taking phentabz if i use wellbutrin and klonopin for depression?


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