Phentermine for Weight Loss

This article will show you everything you need to know about Phentermine. If you have done any research on diet pills, you may have already come across Phentermine. After reading this article, you will be able to understand precisely how it works, what are the ingredients, warnings and any side effects. There are general instructions on how Phentermine is used, but also natural alternatives to Phentermine.

What is Phentermine?

From a chemical perspective, Phentermine is the abbreviation of the technical denomination phenyl-tertiary-butylamine. This psychostimulant drug is part of the amphetamine class, prescribed in the past for weight loss. Phentermine is mostly known for its appetite reduction properties which aid in the weight loss journey together with a healthy lifestyle. It goes best as an auxiliary to exercise and low-calorie food portions.

This stimulant works by having an impact on a specific part of the central nervous system which controls the food appetite. By suppressing cravings, Phentermine proves to be the short-term solution for people who are battling with obesity. Phentermine is currently marketed under various brands across the world, and can only be obtained as a prescription drug in the US. It can be found as Schedule IV drug under the US Controlled Substances Act. Some examples of brands include Adipex, Qsymia, Lomaira, Ionamin, Suprenza.

History of Phentermine

The United States FDA (Food and Drug Association) approved Phentermine for the first time in 1959, as an appetite-suppressing formula.

Throughout the years, Phentermine was commercialized alongside fenfluramine/dexfenfluramine with benefits such as burning fat and subduing appetite. That’s how it got the name of fen-phen, collectively called on the market. By 1996, fen-phen was already prescribed to millions of people.

In 1997, multiple cases of customers who had used the drug, came up to have heart valve problems. Due to these instances, fenfluramine, the substance at fault, was withdrawn from the market. Phentermine was classified as a controlled substance and continued to be prescribed and sold on its own.

Lastly, the company Vivus, combined phentermine with topiramate. Even though, FDA initially rejected the formula, Vivus finally managed to develop one which was approved in 2012.

Phentermine Claims

Phentermine widely conveys the message that it can help lose weight through appetite suppression and energy increase.

By acting upon the brain chemicals (called neurotransmitters), the formula generates a “fight or flight” response inside the brain, which is usually present in very stressful situations. When this response is induced, there are two relevant outcomes: the hunger signal is turned off, the perception of hunger is diminished and appetite is crushed adrenaline is released, stored fat is broken down.

Phentermine claims to provide the starting point and support in a weight loss program. The best results are obtained when combined with a consistent healthy way of living. Watch the video below for a short 5-minute explanation on the benefits of Phentermine:

4. Phentermine Ingredients

Phentermine is an anorectic agent with the molecular formula C10H15N. The process of manufacturing Phentermine is based on benzaldehyde and 2-nitropropane. From a chemical perspective, the condensation product of benzaldehyde and nitropropane is transfigured to the equivalent aminoalcohol. The resulted chloroamine is transformed followed by a catalytic hydrogenation.

Phentermine is a part of amphetamines drugs class which is one of the reasons that it can be bought only with a prescription. The goal of producing Phentermine was to have a strong anorexiant with great results, minus the side effects of amphetamines.

The active ingredient of Phentermine is Phentermine hydrochloride which is a controlled substance. Being a controlled substance, only a doctor can prescribe it and the maximum period of time in which it can be used at a time is 12 weeks.

5. Does Phentermine Work?

According to the majority of the people who have used it, Phentermine is highly effective. These pills are especially good to be used in exogenous obesity weight loss treatment or therapy.

Phentermine has provided great results in weight reduction to millions of people due to their ability to suppress the appetite. With a deficit caloric intake, it would be close to impossible not to lose weight.

By analyzing the way it works, it’s obvious that Phentermine puts a halt on the hunger sensation causing people to eat less. At the end of the day, the calories will be in a deficit, making the body start burning the reserves made from fat cells. People usually tolerate phentermine well, being considered safe if you take it according to the doctor’s recommendations. When the safety precautions are taken into consideration, Phentermine is helpful in fighting obesity.

As a general rule, for great results, each doctor advocates for a continuous healthy lifestyle merged with Phentermine. This drug assists for a short period of maximum 12 weeks until the new habits of eating less will settle in.

The various brands under which Phentermine is marketed are sold by companies such as: iNova, Vivus, Kwang Dong, Gate Pharmaceuticals, More Pharma Corporation, DreamPharma, Barr Pharmaceuticals, Sandoz. They come as capsules, tablets or ODT (orally dissolving tablets).

6. Phentermine Benefits and Results

The persons who benefit the most from using Phentermine are the ones who usually cannot lose weight through traditional methods. When there are external factors affecting the capability to lose weight, Phentermine does the trick.

Phentermine aids with obesity issues but also helps in boosting confidence. When the body weight drops to smaller proportions, activities become easier to perform. Additionally, the mental health is improved due to the newly perceived self-image.

When using Phentermine, the most significant results in pounds dropped will show up in the first few weeks. Afterward, as the body gets accustomed to the new eating portions, results will be seen even after the treatment with these pills is stopped.

Translating the above in numbers, in average, people lost 1-4 pounds per week. Each weight loss journey varies from person to person, some people lose less, others more. The weight loss under Phentermine is also influenced by the life style of each individual. Eating clean, exercising, sleeping and reducing stress are the major elements which will boost the effects of Phentermine.

On the majority of medical websites, Phentermine is reviewed between 8 to 9 starts in terms of efficiency.

The dosage varies from 8mg to 37.5mg, 37.5mg being the maximum that a doctor recommends. According to each person’s body and goals to achieve, the doctor will prescribe the correct dosage and frequency for each individual.

7. Details on Phentermine and Weight Loss

Phentermine is the medication which achieves the effects of eating less and exercising more. Because it acts as a stimulant in the hypothalamus of the brain, norepinephrine is released in the appetite centers. The brain is tricked into this satiating effect, which minimizes the hunger sensation. Cravings are curbed and the body gets a feeling of fullness. The food portions get reduced and calorie intake as well.

Additionally, Phentermine influences the production of adrenaline. This means that the body will have elevated energy levels which will lead to an increase in mobility. Any type of activities will be easier performed when the body is flooded with adrenaline.

In this way, Phentermine leads to an energy deficit. An energy deficit is reached when the number of calories burned is higher than the number of calories ingested. This is exactly how Phentermine influences the weight loss. When the line is drawn, the energy deficit is attained and the body slims down day by day.

The slimming medication will be used together with a doctor-recommended program after a thorough consultation. Only when each person commits to better healthy choices, the weight loss can have extraordinary results which can continue long after the medications stop.

To explain in more technical terms, Phentermine functions as a TAAR1 (trace amine-associated receptor 1) agonist which stimulates TAAR1 sites. The result is the release of norepinephrine, serotonin, and dopamine.

The effects of the neurotransmission consist of:

  • augmented energy levels
  • reduced body fat
  • suppressed appetite

The process of halting hunger perception happens inside multiple nuclei in the hypothalamus: lateral hypothalamic nucleus, ventromedial nucleus and arcuate nucleus. The process of reducing the body fat and getting great levels of energy happens outside the brain through the release of norepinephrine and epinephrine (also known as adrenaline).

8. How to use Phentermine

The most important thing about taking Phentermine is that the instructions given by the doctor must be followed to the letter. Usually, the recommendation is to be taken either on an empty stomach, either 1-2 hours after breakfast.

Depending on each individual’s body, a doctor can adjust the dose from 1 pill to 3 pills per day. However, the maximum dosage of Phentermine that is acceptable is of 37.5 mg.

The dose is provided according to the prescribed form of the pill. For example, for sustained-release capsules, the dose is given one time before breakfast or at least 10-14 hours before going to sleep. As a tip, the pills should be instantly swallowed, not broken down inside the mouth. There can be side effects if the capsules are chewed.

There is also the option of tablets that can dissolve in the mouth. In this case, there is one pill in the morning, before or after breakfast. The pill is placed inside the mouth, on the tongue until it dissipates.

Mornings are the best to take Phentermine because the stimulant will work its magic throughout the day and can keep you alert if you are tired.

The doctor will give this medication only for a short period of time at a time, usually a few weeks.

Additionally, as Phentermine is a part of the amphetamines group, some people may experience withdrawal symptoms when the treatment ends. This is why the doctor should always be consulted before suddenly deciding to stop the medication. Generally, withdrawal reactions were also seen in patients that have taken Phentermine for a longer period of time. In such cases, the doctor usually reduces the dose moderately.

9. Potential Phentermine Side Effects

Phentermine presents side effects on a mild to serious spectrum. The doctor will always check the medical condition before prescribing this medication, however side effects may still show up. The ones that should be reported immediately are:

  • chest pain
  • breathing problems
  • fainting
  • swollen feet
  • inability to carry regular activities

The most popular side effects reported by people include:

  • dry mouth
  • trouble sleeping
  • constipation
  • a headache
  • dizziness

Other side effects less commonly encountered include:

  • blurred vision
  • confusion
  • depression
  • irritability
  • anger

In the case of an overdose, some the side effects consist of:

  • confusion
  • elevated breathing
  • nausea
  • seizures
  • hallucinations

These are a small part of the side effects that can occur from using Phentermine. The doctor will most likely explain everything in detail for a safe use of the medication.

10. Phentermine Warnings and Precautions

Phentermine is not suitable for everyone as there are several precautions and guidelines to be followed, most importantly, people who suffer from: advanced atherosclerosis, alcohol abuse or allergies to amphetamines, methamphetamines and other several elements.

Phentermine is not recommended during pregnancy as the side effects are not known and it may cause difficulties.

As warnings, Phentermine is best avoided in the following scenarios:

  • alcohol: can lead to dizziness
  • diabetes: can influence blood sugar levels
  • hyperthyroidism: can make the condition worse
  • kidney disease: side effects can show up
  • driving and hazardous work: can give dizziness
  • other medications: serious side effects can appear

Phentermine should be taken as a stand-alone medication and the doctor has to always be consulted when taking other medication. There are several treatments that should never be combined due to dangerous side effects.

Phentermine is also not allowed for:

  • children under the age of 18
  • breastfeeding
  • adults over 60 years of age

11. Phentermine Alternatives

Alternatives for Phentermine, there are many weight loss and OTC fat burning supplements that promise great results and work in a similar way. These top recommended alternative solutions for weight loss in 2019 are:


Phen375 helps losing weight by suppressing cravings, burning fat, increasing the metabolism and energy levels. The ingredients used in Phen375 are:

  • cayenne, good for thermogenic properties
  • calcium carbonate maintains the optimal weight
  • caffeine powder gives energy
  • chromium reduces cravings
  • citrus aurantium, promotes highly active metabolism
  • l-carnitine, good for burning fat
  • orchid extract, good digestive function
  • Coleus Forskolii Root, good for the blood pressure


PhenQ focuses on decreasing body fat and having an increased metabolic rate. The ingredients used in PhenQ are:

  • capsimax powder (capsicum, piperine, caffeine and niacin (vitamin B3), used for increasing the body heat
  • calcium carbonate supports a favorable weight
  • caffeine powder removes fatigues
  • chromium diminishes cravings
  • nopal aids fluid retention
  • l-carnitine burns fat


Phen24 is a stimulant-free product that works great for weight loss through five important actions: burns fat, boosts energy, burns calories, reduces cravings and gets a nice sleep. There are two products Phen24 Day and Phen24 Night with the following ingredients:

a) Phen24 Day

  • Caffeine reduces tiredness
  • Guarana Extract gives an energy boost
  • Cayenne Powder, elevates the body temperature
  • Phenylalanine, curbs the appetite
  • Iodine improves thyroid function
  • Manganese helps the processing of fats
  • Zinc Citrate helps at food digestion
  • Copper Sulphate promotes good energy

b) Phen24 Night

  • Glucomannan, gives a satiating sensation
  • Chromium Picolinate, helps with blood sugar levels
  • Biotin, aids to prevent fat accumulation
  • Choline Bitartrate, promotes healthy internal system
  • Molybdenum (Sodium Molybdate), boost energy levels
  • Pantothenic Acid (Vitamin B5), metabolizes food faster
  • Thiamine (Vitamin B1), processes fats and protein
  • Pyridoxine HCl (Vitamin B6), aids in the metabolization of amino acids and proteins
  • Green Tea Extract, amplifies the fat burning hormones
  • Ascorbic Acid (Vitamin C), helps to maintain a healthy body
  •  Griffonia Extract, helps in having a relaxed sleep
  • Hops Extract, great for sleeping disorders

The best part is that none of the above recommendations require a prescription. There is also a money back guarantee of 60 days and high-quality ingredients that work to help you lose weight safely.

12. The Bottom Line – Does Phentermine Work?

Phentermine has proven to be effective for the majority of people that have used it to lose weight. It definitely helps people who cannot get thinner through the usual methods of eating less and exercising. The appetite suppression and boots of energy levels look like great options when going for a slimmer figure.

However, at the same time, it also has considerable side effects and warnings which can make it hard to get accustomed to the product. Furthermore, Phentermine works on a short-term with only some promises for long-term success.

Taking everything into consideration, Phentermine can be a solution to weight loss, but at the same time, there are other natural viable options. These options promise great results with little to no side effects. In the end, it depends on each person to choose what they consider best for themselves.