My love of diet products is bested only by my passion for reviewing them. This is why we took a close look at Phentermine ingredients, side effects, and scientific studies. We additionally examined hundreds of user comments and dieter reviews. Lastly, we compressed all of the feedback and facts we found to give you the info you need.
What is Phentermine?
To begin, Phentermine is a weight-loss medication available by prescription only. Although instructions vary, it’s usually taken once each day, before breakfast and supposedly decreases appetite. That assists by suppressing appetite.  The blister pack makes it easy to take on-the-go.
Phentermine was first available in the United States in 1959 and is currently manufactured by several companies.
Side Effects – “Something to Consider?”
First off, we have to take potential Phentermine side effects into consideration. “Appetite suppressants can help improve long-term weight-loss,” said our Research Editor. “But, they can also lead to side effects such as restlessness, headache, dizziness, sleep problems, diarrhea, upset stomach, constipation and dry mouth.”
One customer commented, “The sleepless nights and irritability is so not worth it. You have to remember the side effects are no good.” 
When we look at the other side of things, there are some patients who did not experience Phentermine side effects.
As one put it, “I am not hungry. No headaches, no side effects.”
Another shared, “It was amazing, minimal side effects, mostly dry mouth from not drinking enough water.”
Customer Complaints With Phentermine – “Problematic?”
We found several negative issues in Phentermine reviews. One dieter stated, “I’m always tired with no energy and really weak feeling all the time.”
Another person said, “I took 1/2 a pill and about 5 hours later I felt sweaty and felt a thud in my chest.”
We also found some support. One user said, “This is the only pill that works for me. I am very happy with my results.”
“I took phentermine before and the weight came off even though I didn’t exercise,” reported another.
The research we’ve conducted has shown if there is some particular aspect of a diet pill considered concerning, like customer complaints, the chances of long-term success are not good. So, if Phentermine isn’t received well by customers, we become skeptical about it.
The Science – “Solid?”
There are clinical studies supporting the appetite suppressing effects of Phentermine . Although there is research showing it works, the directions only state to use on a short-term basis. This may not be beneficial for those who have larger amounts of weight to lose . At DietSpotlight, we like seeing solid science backing the claims of a company. But, if the research doesn’t point toward long-term results, we often see a big red .
The Bottom Line – Does Phentermine Work?
So, will you see Phentermine results? Well, we like the longevity as a product and some positive comments we saw found, but we’re concerned about it because the research shows short-term results. Also, we’re a bit hesitant due to customer complaints and mentions of negative side effects .
If you’d like to lose those extra pounds, we suggest going with a supplement with no talk of harmful side effects and clinically-tested ingredients shown to work.
Among the best products we’ve seen this year is our product called Leptigen. The formula contains four clinically-tested ingredients. Results are often found in publications such as The American Journal of Clinical Nutrition and the journal Obesity [6, 7, 8, 9].
Also, we’re so confident that you’ll love our supplement, that we’re offering a Special Trial Offer, which is great sign.
Previous Phentermine Review (Updated September 20, 2014):
Phentermine - What You Should Know
Phentermine is well known as an effective treatment for those who have significant weight loss needs. It is typically prescribed along with a strict regimen of exercise and diet, as well as along with behavior modification techniques. It works by releasing chemicals in the brain that help control the appetite without leaving the user feeling deprived. Phentermine for weight loss is intended for short-term use and to produce big results in that shorter period of time.
In 1997 Fenfluramine and dexfenfluramine (also known as Fen-Phen, which was a popular weight loss drug at this time) were voluntarily removed from store shelves per FDA recommendations. Fen-Phen caused a very small percentage of people to have near-fatal or fatal heart complications. Phentermine was not one of the drugs removed from shelves as a result of the problems related to Fen-Phen. It is, however, listed as a controlled substance in some countries because it is considered to be an addictive medication.
List of Ingredients in Phentermine
Phentermine, hydrochloride, n-butyl, isopropyl alcohol, ethyl, and propylene glycol. Phentermine Ingredients have a possibility of being addictive.
The diet pill Phentermine is considered to be addictive and is classified (in many countries) as an amphetamine as a result of its addictive properties. It is also classified as phenethylamine. It works as a stimulant that transmits the message that the body isn't hungry to the brain. It is a highly effective medication and can bring about big results fairly quickly, but it should never be viewed as anything other than a very last-resort solution for clinical obesity.
Phentermine isn't harmful if you keep in close contact with your physician while using it, and you use it only as directed. Unfortunately, problems arise too frequently when people take Phentermine for weight loss repeatedly throughout the day and end up not eating or sleeping.
Phentermine Diet Pills Advantages
- Signals the brain that the body isn't hungry.
- Effective appetite suppression.
- Under proper supervision, a course of Phentermine also encourages healthy lifestyle rather than reliance on medication.
Phentermine Weight Loss Pills Disadvantages
- Has a rather extensive list of severe potential side effects. (See Phentermine Side Effects.)
- Can cause a Phentermine high.
- Can only be used for short-term weight loss.
- There is a risk of addiction.
- Phentermine is strictly regulated by various agencies, making it only suitable for treating clinical obesity.
Before we dive into the conclusion, Creative BioScience 30 Day Diet comes off as another good weight loss product used to help you lose a pound a day. You will not find many drugs on the market that promise the results that Phentermine does. It may not be an easy drug to get your hands on, but the effectiveness of this medication makes it a gem for those who need to lose a large amount of weight fairly quickly for health reasons. This is definitely not a medication for those struggling with vanity pounds, but if you have tried every other diet on the planet and failed, you have very little to lose by discussing Phentermine with your doctor. We highly recommend trying safer, non-prescription alternatives that combine appetite suppressants with fat burners before considering something as strong as Phentermine, but if your doctor recommends it, it could be the weight loss aid you're looking for. Aside from the diet pill Phentermine, IdealShape is a weight-loss system consisting of meal replacement shakes, snacks and supplements, and when paired with exercise there’s a good chance for weight-loss.
Phentermine Questions & Answers:
After examining hundreds of user comments about the diet pill Phentermine, we created this helpful FAQ.
What are the side effects of Phentermine?
Phentermine diet pills side effects reported by some users include dry mouth, constipation, headache, irritability, mood swings, nervousness, anxiety, nausea and upset stomach. 
What is in diet pill Phentermine?
The only Phentermine ingredient is phentermine hydrochloride.
What is the active ingredient in Phentermine?
The active ingredient in Phentermine is phentermine hydrochloride.
Does Phentermine really work?
Yes, Phentermine for weight loss does work. Studies have shown individuals using the medications have lost weight. But, the company states that the medication is only for short-term use.
How much does a bottle of Phentermine cost?
The cost of a bottle of Phentermine depends on the pharmacy where purchased, generic or branded, as well as if your insurance offers a discount.
How do you take Phentermine?
You should take Phentermine based on your physician’s instructions.
Can I take Phentermine for weight loss if I have a health condition?
Women who are pregnant or nursing, those with health conditions, anyone using prescription medications or under 18 years of age should speak with a healthcare provider prior to taking any weight-management supplement, including Phentermine.
What do users like about Phentermine weight loss pills?
We noticed that some users liked seeing some weight-loss while taking Phentermine.
What do users NOT like about Phentermine?
Some users didn’t like the side effects experienced while taking Phentermine.
How does Phentermine work?
It sparks a release of adrenaline that stimulates energy, food digestion, and energy production.
Who makes Phentermine weight loss pills?
The branded versions of Phentermine is made by Medeva Pharmaceuticals and Gate Pharmaceuticals. Multiple pharmaceutical companies make the generic version.
How do I contact the Phentermine customer service department?
You can contact the Phentermine customer service department by sending an email through the feedback form on the official website.
Can I contact Phentermine through social media?
Is Phentermine an amphetamine?
No, Phentermine isn’t an amphetamine; it’s considered an appetite suppressant. 
Is there a difference between the yellow and blue/white Phentermine diet pills?
Yes, there’s a difference between the yellow and blue/white Phentermine capsules. The color varies by manufacturer and whether or not it’s branded or generic.
Can I purchase Phentermine diet pills without a prescription?
No, you can’t purchase Phentermine without a prescription.
Does Phentermine come with a guarantee?
There’s no mention of a guarantee with Phentermine weight loss pills. You can contact the customer service department or your local pharmacy for additional details relating returning the medication.
Many supplements claim weight loss can be achieved through means of curbing appetite, increasing energy levels and dropping pounds on the scale. Leptigen‘s ingredients have been clinically tested to prove it’s one of the best weight loss supplements that work effectively.
- 1. Phentermine (2013). Medline Plus. October 27, 2016.
- 2. Long‐term effects of weight‐reducing drugs in people with elevated blood pressure (2015). Cochrane Database of Systematic Reviews. November 2, 2016.
Phentermine User Tips:
While we were researching Phentermine we noticed that the people who have used it have a lot to say. We examined thousands of comments and reviews to pick out the best tips to help you learn more about this product.
“I pulled the powdered capsules apart and sprinkled ½ the powder into my coffee and just sip on it. I had to build up to the full thing.” Faith
“You have to stick to a diet for this to work well.” Sarah
“This worked BUT I completely changed my diet. No bread, candy, soda, and very few carbs.” Cora
“I wouldn’t recommend this if you already have depression because it can make it worse for you even though it does help with weight loss.” Nicholas
“I don’t sleep well if I take this too late in the day. It’s really important to take it first thing.” Andy
“I have to split up the dosage to reduce the fast heartbeat. The first three weeks are the hardest but then it gets easier.” Alma
“The first day I had dry mouth and woke up to my heart fluttering. After a few weeks that got better.” Rusty
Phentermine Scientific Abstracts:
Phentermine is commonly used for short-term treatment of obesity alongside certain lifestyle modifications. Topiramate has been approved for the treatment of epilepsy, migraine preventative in addition to inducing weight-loss. A combination of low-dose extended-release topiramate and phentermine has been approved in the US for the chronic treatment of obese and overweight individuals to be used in conjunction with lifestyle modifications. Analyzed cardiovascular data for the long-term treatment and use of phentermine and topiramate has shown that this mixture could be a safe (and effective) choice for decreasing weight for overweight and obese individuals at a low cardiovascular risk. 
Long-term use of medications used for obesity, when administered alongside lifestyle interventions, provide extra weight-loss as opposed to placebo ranging from around 3% of starting weight for orlistat and lorcaserin to around 9% for top-dose phentermine/topiramate-ER (15/92mg)-at one year. The amount of participants accomplishing clinically significant weight-loss (≥5%) range from 37 to 47% for lorcaserin, 35 to 73% for orlistat, and 67 to 70% for phentermine/topiramate-ER. As far as cardiometabolic risk factors are concerned, all three have shown greater potential than with placebo. However, no medications administered to treat obesity have displayed the ability to reduce cardiovascular mortality. Medications that are approved for the long-term treatment of obesity, when used accordingly, lead to significant mean weight-loss and the increased chance of accomplishing meaningful weight-loss within 1 year as opposed to placebo. 
Phentermine/topiramate ER is a useful, safe and effective weight-loss medication that can deliver (as well as sustain) around 10% of body weight-loss. This is considered a great achievement in the development of pharmacotherapy of obesity. Phentermine/topiramate offers an effective option to use concurrent to lifestyle change and surgical procedures and enables a comprehensive medical example for treating obesity. When considering an approach to the treatment of an overweight or obese patient you should identify who will benefit from the therapy the most; establishing therapeutic targets and goals, cardiometabolic or mechanical complications, and selection of treatment strength to accomplish weight-loss goals. Obesity is considered a lifelong, chronic disease that could need therapy for a prolonged amount of time. A combination of protracted clinical trials and clinical experience is required in order to further assess longer-term effects and plans which will employ options for treatment in an effort to sustain weight-loss over decades. 
There was a significant difference in individual, as well as total scores, between subjects treated with phentermine and the subject who were dependant on amphetamine. Cravings and withdrawals were gone entirely in those treated with phentermine. A sudden halt in long-term phentermine use does not induce withdrawals similar to amphetamine. 
- 1. Cardiovascular effects of phentermine and topiramate: a new drug combination for the treatment of obesity (2014). Journal of Hypertension. October 25, 2016.
- 2. Long-term Drug Treatment for Obesity: A Systematic and Clinical Review (2014). National Institute of Diabetes and Digestive and Kidney Diseases. October 25, 2016.
- 3. Phentermine and topiramate extended-release: a new treatment for obesity and its role in a complications-centric approach to obesity medical management (2013). Expert Opinion on Drug Therapy. October 25, 2016.
- 4. A Study of Abrupt Phentermine Cessation in 5 (2011). American Journal of Therapeutics. October 25, 2016.
Phentermine Side Effects:
It’s easy to think that the natural solution is the option without side effects, but that isn’t always the case. With any formula there’s a risk of a negative reaction, and while Phentermine side effects are fairly uncommon, it doesn’t mean some users won’t experience a reaction.
Chest pain has been described as a dull ache or a sharp stabbing sensation in the chest. Other forms of this effect are a crushing or burning in the chest, as well as pain in the jaw. Chest pains could result in cold sweats, shortness of breath, and nausea. 
What causes chest pain?
Chest pains are most commonly associated with angina, which can occur with no known cause. Heart attack could be another issue as well. Heartburn, gallbladder problems, and swallowing disorders could all be a cause of chest pains.
Headache is a pain in the head or neck region, described as dull, moderate, or severe. Headaches are common, but depending on length and severity of pain, could be the symptom of a more serious medical condition.
What causes headache?
A headache is caused by an irritation of pain sensitive structures in the head. Nerves, blood vessels, and tissue can become inflamed or irritated, sending pain signals to the brain. Overexertion, exercise, or stress are all common causes. Other factors can be blunt force trauma, tumors, or medications.
Constipation is the body’s inability to make a bowel movement as easily as it should. This can cause irritation and sweating, nausea and bloating in some cases.
What causes constipation?
When the body absorbs too much moisture, stools can become dry and harden before they pass. Changes in diet, irritable bowel syndrome, dehydration, lack of fiber, and inactivity can all cause constipation.
Dizziness is the feeling of unsteadiness, lightheadedness, and wooziness. Dizziness is the sensation of moving, tilting, floating or whirling (sensations also associated with vertigo). These feelings can happen while laying down or standing still.
What causes dizziness?
Many factors can play a part in dizziness, including head injury, ear infections, and medications. Low blood pressure and other factors that affect the brain or inner ear can also cause problems. 
Phentermine side effects are rare, but there have been a few suggestions of dizziness, constipation, and headaches, among others. In an effort to safeguard against any possible negative reactions, it’s always best to talk with a doctor before taking any supplement or medication. This is especially true if you are pregnant or nursing, under the age of 18, have a medical condition of any kind, or are taking prescription medications.
Phentermine is a prescription weight-loss supplement that is supposed to suppress appetite, thus, promoting weight-loss. Even though side effects aren’t always certain, we still went out and found comments from users who experienced them.
“I took another half the next morning (today) after waking, maybe an hour later I had crazy chest pain, I could start feeling it in my back and my jaw hurt.” Ange
“I have been taking this for only two days both days I have had a real bad headache.” Tomeka
“I took a whole pill and I’m feeling just a little bit of off and on chest pain.” Mandi
“I do however have some chest pain on the left side and my muscles are fatigued.” Nancy
“Day 1, I was hungry, day 6-8 I became nauseous, and had pains in my heart, became tired, and so sick.” Megan
“I had tremors and felt like my heart was beating out of my chest and extremely dizzy for about three days.” Allie
“In the beginning of taking it, I had trouble falling asleep…and occasionally I would feel light-headed and dizzy…” Dena
“I have been taking Phentermine for a month and I have had a bad itchy rash ever since.” Shana
“It has made me have a few nights I woke up and couldn’t sleep…I also had terrible constipation a couple times.” Charlie
“Had terrible mouth sores bad bloating and terrible constipation.” Leslie
Looking for a supplement that doesn’t give you irritating side effects? We have one you may want to check out. Leptigen is made with clinically tested ingredients and supported by users reviews that consistently report weight-loss.
Dieters are buzzing about phentermine, but we wanted to look deeper into the potential phentermine side effects to give users the entire story. We carefully checked out each and every ingredient, looking for science and clinical facts. We condensed and summarized the information to give you the bottom line.
What You Need to Know
First off, phentermine is a prescription appetite suppressant. You take the medication once daily after breakfast. Dosages range from 15 mg to 37.5 mg. With regular use, it is supposed to boost weight-loss. There’s no problem taking the pills anywhere because they are relatively small and portable.
The medication, with a history dating back to 1959, is approved by the FDA, which is necessary. You need a prescription to purchase the pill at your local pharmacy or online. We like that it’s been available for more than 30 years, but read on…
Contraindications – You Can’t Take That with That
Our first issue with phentermine side effects surrounds potential interactions with other medications or the human body. “Dieters who go to a physician in hopes of finding help losing weight are looking for a safe alternative,” explains our Research Editor. “They are not willing to exchange weight-loss for serious phentermine side effects.”
According to the National Institutes of Health, the medication should not be taken with MAOIs, insulin, oral diabetes medications or adrenergic neuron clocking drugs. It is also important to skip alcohol as that can cause an adverse side effect. There’s also the issue with phentermine side effects in the case of other medical conditions like hyperthyroidism, glaucoma, pregnancy and any cardiovascular condition.
Dieter Complaints – Should You Take the Chance?
We’re also highly concerned about the hundreds of dieter complaints associated with phentermine side effects. “Other than the normal side effects such as dry mouth, I experienced extreme anxiety, short term memory loss, and terrible constipation. I tried getting off the pill and had withdrawals that caused me to fall asleep while driving and during work,” one taker describes.
Another user explains, “In the first week I’ve had a pounding chest all the time, have slept at most 3 hours per night, fairly bad depression and irritability. Depression so bad that I’d burst into tears when I made a silly mistake at work at my computer which is an embarrassing look for a fully grown adult man.”
Phentermine side effects are the top dieter complaint, “I did and do experience some of its side effects such as insomnia, dizziness, dry mouth, headache, unpleasant taste, restlessness, increase in blood pressure, heart palpitations, and excess energy.”
In our experience, it takes only one small issue, like contraindications, to offset your chances of long-term success. If phentermine side effects are as serious as dieters explain, you’ll have to weigh the pros and cons carefully.
Because this is a prescription medication, the FDA has reviewed and approved it for weight-loss. It also means there are detailed reports of potential phentermine side effects. While appetite suppression is proven in clinical research, so are the negative reactions. It’s also a concern that some dieters report hunger returning after only a few months.
The Bottom Line
We’re always up for looking deep into a weight-loss medication, and specifically into phentermine side effects this time around. We like that the FDA has approved the pill and some dieters report losing weight, but we can’t recommend it because of the risk of negative reactions and contraindications with medical conditions and other physician-prescribed treatments.
If it’s your time to lose weight, we suggest going with a supplement offering a clinically proven list of ingredients with no reported side effects.
Among the best products we’ve found in 2016 is Leptigen. The formula is packed with ingredients proven in published clinical research to help speed up metabolism and boost fat loss. There are no reported adverse side effects, but we were thrilled to find numerous dieters reporting great results.
Also, the makers of Leptigen show confidence in the supplement by offering a special trial offer, not something you see every day.
Phentermine diet pills are prescription appetite suppressants taken between one and three times a day. Adipex diet pills are another name you may encounter.
Phentermine Ingredients and Supplement Facts
Serving Per Container: 30
|Amount per Serving||% DV|
|Phentermine HCL||15mg to 37.5mg||*|
Other Ingredients: None
We looked into Phentermine ingredients in order to give you the facts you want.
Phentermine is an appetite suppressant that is meant to be used for about three months. It is used primarily in weight-loss and dietary supplements.
What Is It Supposed To Do?
Phentermine is an appetite suppressant, which means it will make you less hungry. In theory, this is supposed to make you eat less and therefore, causing you to lose weight.
In a study published in Yonsei Medical Journal, researchers concluded, “Conclusively, we can suggest that short-term phentermine administration can induce significant weight reduction and the shortening of waist circumference without clinically problematic adverse events on relatively healthy obese people, by this study.” 
Another study had the same results, noting that phentermine may help in the long term treatment of obesity, but not necessarily inducing weight-loss. Published in The American Journal of Clinical Nutrition, researchers stated, “PHEN/TPM CR in conjunction with lifestyle modification may provide a well-tolerated and effective option for the sustained treatment of obesity complicated by cardiometabolic disease.” 
However, a study published in A Peer-Reviewed Journal for Managed Care and Hospital Formulary Management noted the lack of weight-loss results phentermine has as a main ingredient in a supplement, stating, “Currently, no studies have compared the efficacy and safety of this combination product with either active ingredient alone as monotherapy or with other available weight-loss agents.”
In yet another study, published in Expert Opinion on Pharmacotherapy, researchers said, “Phentermine-topiramate ER, however, was associated with increased heart rate, the clinical significance of which is being investigated in an FDA-required CVD outcomes study. The medication also must be used with caution in women of child-bearing age because of an increased risk to infants of oral cleft.”
If you are looking for a supplement with clinically-tested ingredients that promote weight-loss without the harmful side effects, Leptigen may be for you. It is one of the top fat burners out there with amazing user reviews.
Why are people talking about phentermine? This is something we needed to figure out, so we take a deep look at phentermine ingredients. We’ll pay close attention to the scientific research. Furthermore, we’ll turn toward customer comments for the facts. Then, we’ll summarize the info to give you the bottom line.
What You Need to Know
To start, phentermine is a prescription weight-loss drug containing oral phentermine hydrochloride. The dosage is controlled by a physician and includes 8mg, 15mg, 18.75mg, 30mg and 37.5mg. The amount you take is based on your doctor’s recommendation. The pill supposedly helps you lose more. One of the benefits is that it’s easy to use.
The product, first discovered in 1959, has been clinically tested, a positive sign. You can only buy the pill with a prescription. We like that the medication is FDA-approved and that we located some positive customer comments, but read on…
Ineffective – “Pounds Not Dropping Off?”
The first concern about phentermine ingredients was ineffectiveness. “You’ve thrown that money down on the counter and now you want to see results,” said our Research Editor. “If you see nothing, that’s when the doubt starts creeping in.”
“Now I am at a plateau I haven’t lost any weigh in fact today I gained .5 lbs. I’m so depressed,” said a user.
“But since last week I am hungry again. And then my weight started to go up,” reported a dieter.
Side Effects – “Feeling Terrible?”
According to dieter comments on the web, Phentermine side effects tend to be severe. “I have never suffered any [reactions] like I do with this. The dry mouth, dry lips, constipation, headache, feeling that pupils are dilated enough is enough. Last night I had a weird head ache. It was like a dehydrated headache, and an upset tummy and was not feeling hot. So after almost 3 weeks on pill I am done” offered one comment.
“The side effects…and I’m only going to take this until this bottle is gone. Chapped lips, dry mouth/ constant bad taste in mouth and constipation,” said a customer.
“The side effects I had gave me moment for pause. First, hands were cold and sweaty. Second, my breath was death. But the next one was weird. I felt incredibly emotional, in a bad way. I almost felt like crying all day. And I found myself not to be my cheery self. It was like I had instant depression,” reports a user.
Throughout our research, we’ve concluded that something small, like side effects, could derail long-term success. If you notice phentermine causes negative reactions, will you continue to use it?
Does the Science Tell the Whole Story?
In order to be FDA-approved, phentermine must be supported by clinical research. But the science also shows that side effects include chest pains, dizziness, headache and trembling and others. At DietSpotlight, we look for studies proving a medication is free from potential negative reactions. If science can’t give us that, we turn our heads.
The Bottom Line – Does Phentermine Work?
Now what you’ve been waiting for…drum roll please. We appreciate that the FDA has approved this one and that we located some favorable customer comments, but we have reservations about the product because the research proves adverse reactions. We also have concerns about ineffectiveness and potential side effects.
If you’d like to shed those extra pounds, we suggest going with a product that doesn’t require a prescription that contains ingredients supported by published clinical research that aren’t associated with negative side effects of any kind.
Among the best products we’ve seen in 2016 is one called Leptigen. The supplement contains a formula consisting of a four-ingredient proprietary blend, which has been shown in published scientific research to help promote fat loss and ignite metabolism. There’s no chatter about negative side effects and dieters commenting on the web are noticing excellent results.
Also, the company that makes Leptigen is providing a Special Trial Offer, an excellent sign of confidence in the product.
- 1. Effects on Weight Reduction and Safety of Short-Term Phentermine Administration in Korean Obese People (2006). Yonsei Medical Journal. October 30, 2016.
- 2. Two-year sustained weight loss and metabolic benefits with controlled-release phentermine/topiramate in obese and overweight adults (SEQUEL): a randomized, placebo-controlled, phase 3 extension study. (2012). The American Journal of Clinical Nutrition. November 10, 2016.