Is Phentermine Dangerous to Take for Fat Loss?

January 9, 2024 |

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This article will provide you with all the information about the safety of Phentermine and the potential harm it can cause to different body systems.

So, yes, phentermine usage is associated with a risk of adversities during pregnancy, heart diseases, brain injuries, and psychological issues.

Though Phentermine is an effective hunger suppressant, we cannot neglect the possibility of serious health problems that may arise due to this anorexic drug.

In the following sections, we will discuss the side effects of Phentermine on cardiovascular and central nervous systems and its possible impacts on the health of pregnant women and their children as well.

Moreover, we’ll also talk about the probability of death from Phentermine usage according to the FDA monitoring report.

And while those facts might have you looking for a safer alternative to Phentermine that provides better results without compromising health safety, we’ll also provide you with a more suitable diet supplement.

Let’s dive into it without any further ado.

Is taking Phentermine dangerous?

Although Phentermine is safe when used in small amounts according to the prescription, it can still lead to harmful consequences if you have underlying health issues.

It is given FDA category X and is contradicted for pregnant women, especially due to its negative offshoots on pregnancy outcomes.

Its common side effects are thirst, nausea, headache, constipation, dry mouth, Urticaria, insomnia, and palpitations. And serious adversities include disorders of the brain and heart.

Next, we have discussed various scenarios where Phentermine can put your health safety at peril.

Is Phentermine dangerous during pregnancy?

Yes, it can negatively impact the mother’s health and cause anomalies in the unborn baby.

pregnant woman

Effects on pregnant women

1. Gestational Diabetes

A high rate of gestational diabetes mellitus (GDM) is seen among those women who took phentermine/ fenfluramine during the first trimester of pregnancy.

GDM is a risk factor for several long-term health problems for both the mother and the child.

Research analysis infers that children whose mothers developed diabetes during gestation have 2-8 folds higher chances of metabolic syndromes, becoming overweight, type 2 diabetes, increased insulin resistance, and impaired pancreatic secretions than children whose mothers did not experience GDM.

2. Insomnia

Phentermine users not only eat lesser but also sleep lesser, as insomnia is one of its common side effects.

Lack of quality sleep subsequently reduces the quality of lifestyle because you will feel tired and dizzy all day long.

Such feelings can make conception challenging as the gravida needs more rest due to enormous physiological changes occurring in her body.

Besides causing restlessness, sleep deprivation induced by diet pills can make delivery more difficult.

Clinical observations infer that insomnia increases the probability of longer labor, increased labor pain, and higher rates of C-sections and pre-term deliveries.

Sleeplessness is possibly linked with pre-term births and postpartum depression as well.

Harmful effects on the unborn baby

1. Cephalic cysts

If the mother uses Phentermine during pregnancy, it can interfere with the fetal nervous system, producing cephalic anomalies like larger head circumference, cysts, etc.

One such case was reported for a young lady of 24 who delivered a baby girl with bilateral porenchephallic cysts.

She had taken Phentermine in the first two trimesters when she was not aware of her pregnancy.

It is suspected that Phentermine has caused a prenatal stroke in the baby, due to which cephalic cysts were formed.

2. Neural tube defects

Phentermine and other anorexic drugs used by mothers before or during conception can produce structural abnormalities in their unborn babies.

This suspicion was confirmed by this systemic research paper that showed a positive association between weight loss drugs and congenital disabilities, especially neural tube defects.

Is Phentermine dangerous to your heart?

Yes, Phentermine can affect heart function adversely.

Its most common impact on the heart is an increase in heartbeat and palpitations, likely caused by a high level of dopamine induced by this drug. Also, phentermine-containing drugs are to boost the heart rate, as reported by FDA.

Other negative effects of this anorexiant on the heart and circulatory system are relatively rare, but the following case studies indicate potential risks;

1. Valvular heart disease

Phentermine-fenfluramine combination is also known to cause valvular heart disease.

According to a pharmacological study, negative effects of phentermine-fenfluramine were seen in women that had no prior history of heart problems.

When these valvular cardiac tissues were examined in detail, a plaque-like encasement was found that is possibly produced due to these weight-loss supplements.

2. Pulmonary hypertension

Phentermine can also affect heart functions indirectly. Its tendency to raise blood pressure can lead to hypertension, especially in pulmonary blood vessels.

Increased blood pressure forces the heart to pump harder, potentially harming cardiac tissues.

Hypertension also reduces the flexibility of coronary arteries, which can cause angina or cardiac arrest

3. Ventricular fibrillation

Phentermine usage increases the risk of arrhythmias in lower heart chambers, making heartbeats irregular.

This condition was reported in a 70-year-old woman who experienced recurrent ventricular fibrillation after taking Phentermine.

It was also reported that she had an underlying cardiac problem (coronary artery vasospasm) that, combined with Phentermine hypertensive effects, caused arrhythmias.

Elimination of the symptoms upon stopping the dosage proves its association with the disease.

What are the effects of Phentermine on the brain?

It may cause physical brain injuries and stroke and also increases the risk of psychological ailments.

As Phentermine is a methylated amphetamine that acts as a CNS stimulator, it triggers dopamine release in the brain.

And a boost of dopamine is associated with appetite suppression and cognitive excitability. Resultantly, these diet pills will make you happier and less hungry in the short term.

However, when the dopamine level remains high for a long time, its stimulatory actions interfere with mental health, possibly leading to depression and anxiety.

Following health issues might be caused by Phentermine’s effects on the brain:

1. Stroke

Phentermine usage increases the risk of stroke, especially in individuals with a history of neural ailments or brain injuries.

Recent case studies provided the history of two women with a mild probability of cerebrovascular issues when they initiated dieting and phentermine intake. They suffered from an acute stroke after using diet pills for some time.

This serious disorder is caused when oxygen supply is stopped to a portion of the brain due to blockage or bursting of cerebral arteries.

Such vascular injury is probably caused by a sudden boost in blood pressure due to a high surge of dopamine. However, further research is required to clarify the association between phentermine and stroke risk factors.

2. Psychosis

As discussed, being sympathomimetic-amine, Phentermine plays stimulatory roles; hence, its overuse is likely to cause mental delusions, stress, and anxiety.

Similar depressive offshoots were observed in a 25 years old lady when she took Phentermine in a weight loss program.

Such psychotic episodes are usually recurrent and impair the patients’ social behavior and working abilities for the time being.

3. Dyskinesia

Phentermine is also associated with the onset of Tardive Dyskinesia and Parkinsonism in one incident.

Again, the blame is on its stimulatory properties because neural activity by artificially triggered neurotransmitters can result in drug-induced movement disorder of jaws, tongue, and lips.

According to a study, an overweight man of 56 years experienced tongue thrusting and unilateral tremors in his right hand. He has had a family history of Parkinson’s disease, and stimulant intake has probably initiated the early onset of the inherited ailment.

Is expired Phentermine dangerous?

No, there is no evidence suggesting that Phentermine becomes toxic after the expiry date.

But like most other medicines, it will gradually lose its potency after expiration. So, outdated pills would not be that much effective for appetite suppression.

To be on the safe side, it is better to avoid expired drugs and instead discard them properly.

We have a complete blog post about this, so in case you want to know more about the efficacy and safety of expired Phentermine here.

How long can you take Phentermine safely?

Phentermine is prescribed for short-term usage, usually for a few weeks. It is suggested that you do not take it for more than three months.

Due to related adverse effects, Phentermine is only provided on a doctor’s recommendation, and it’s best to only take the dose according to the prescription because overdosage and long-term use can be harmful.

Can you die from taking too much Phentermine?

Yes, phentermine overdose can lead to death, although such incidents are quite rare.

can you die from taking phentermine

As we talked about earlier, this amphetamine is associated with pulmonary hypertension.

Hence, if your intake exceeds the limits, it will overburden the cardiovascular system, possibly leading to death following a serious cardiac arrest.

There are more chances for such adversities if you already have underlying heart problems. Furthermore, the risk of stroke increases by Phentermine over usage, which might cause death.

According to research where 13,972 participants on phentermine weight loss therapy were monitored, 5 deaths (0.3% death rate) were reported associated with the drug.

Similarly, phentermine drug label statements confirm the probability of death due to over-usage. Also, FDA lists Qysemia (phentermine and topiramate) abuse as a probable factor for sudden death.

Safe OTC Alternative to Phentermine

As the negative effects of phentermine therapy are pretty severe, you should be thinking by now, is there any safe alternative that could offer the same weight loss efficacy?

To make it easier for you, we researched and tried, and tested a stimulant-free diet pill- PhenQ, that can help you shed extra pounds without making you seriously ill.

Due to its safest composition, it is an over-the-counter drug, and you can take it without a prescription.

Let’s have a closer look at its formulation and see the effectiveness of its components in weight loss;


PhenQ is a series of dietary supplements manufactured by Wolfson brands. Its products include safe weight loss pills and nutritious meal replacement shakes.

PhenQ pills contain a well-balanced mixture of L-carnitine fumarate, α-Lacys reset, nopal, and capsimax powder. All these ingredients are natural, safe, and vegan-friendly.

  • L-carnitine fumarate

L-carnitine fumarate has the largest proportion in its formulation. It is the ingredient that makes PhenQ an excellent appetite suppressant.

Carnitine is scientifically proven to decrease body weight, BMI, and fat deposits.

Research shows that it has anti-obesity properties and significantly helps in weight loss.

Numerous positive reviews of the product indicate its weight loss efficacy, showing that users have lost up to 44 Ibs in just 3 months of PhenQ usage.

  • α-Lacys Reset

PhenQ is not just an appetite suppressant like Phentermine. Rather it is a whole weight loss supplement. Because it also burns stubborn fats and prevents future fat deposits.

Its constituent α-Lacys reset is credited for its wonderful thermogenic properties. This blend of cysteine and alpha-lipoic acid effectively burns body fats without producing any harmful effects.

ALA (Alpha Lipoic Acid) is a cofactor with neuroprotective characteristics. It tends to reduce the appetite and also speeds up metabolic reactions.

The synergistic compound (cysteine) is a proteinogenic amino acid that creates a sensation of ‘fullness’ and keeps you from eating insatiably.

It minimizes your tendency to overeat by reducing ghrelin (the hunger hormone) level in the blood instead of affecting neuro-stimulants like serotonin or dopamine levels to suppress appetite.

  • Nopal

The third miracle ingredient of PhenQ is nopal. It contains fibrous extracts from the nopal cactus, which not only dissolve stored fat but also reduce further built-ups by reducing cell adiposity.

A randomized clinical study showed that it also prevents the absorption of fats into the bloodstream because it positively affects gut microbiota and fat excretion through feces.

  • Caffeine and herbal extracts

It also contains a small amount (145 mg per serving) of caffeine to take advantage of its energy and metabolism-boosting properties.

But you do not need to worry about the BP raise and other harmful effects of this stimulant because its proportion is very minimal.

The approved safe limit for daily caffeine consumption is three times higher than the amount present in one tablet of PhenQ. Plus, there are no other stimulants in it.

Moreover, Capsimax powder (capsicum and piperine extracts) and various vitamins and minerals make its benefits many folds.

Where to buy it?

It is available on their official website.

(We’d recommend you not to buy it from other third-party sites because, given its widespread popularity, many fraudulent sellers have entered the market and you might end up paying real money for a fake product. Not to mention that the safety and effectiveness won’t be promised either.)

  • One bottle comes for $69.95 and contains 60 tablets.
  • The supplement becomes cheaper when you buy in bulk. Its price for (2 bottles+ 1 free) is $139.90 and for (3 bottles + 2 free + free Advana cleanse) is $189.95.


  • An all-natural drug
  • Low-caffeine
  • Gluten-free
  • Vegan-friendly
  • Effective fat burner
  • Discount deals on bulk purchases


  • Not suitable for pregnant or lactating mothers
  • You can only get your hands on it if you’re 18+

Final Thoughts

Anorexiant compounds like Phentermine and amphetamines are useful when you have trouble losing weight. But these weight loss solutions can also create some health problems.

Phentermine can affect your heart, central nervous system, mental well-being, pregnancy, and the development of your unborn baby.

Its impact can be as serious as to cause sudden death!

So, it’s better to stay connected with your doctor when taking such medicines and follow his recommendations.

To get the benefits of diet pills without the risks mentioned above, you can choose a safer alternative like PhenQ.

Important Disclaimer: The information contained on MAX HEALTH LIVING is intended for informational and educational purposes only. Any statements made on this website have not been evaluated by the FDA and any information or products discussed are not intended to diagnose, cure, treat, or prevent any disease or illness. Please consult a healthcare practitioner before making changes to your diet or taking supplements that may interfere with medications.

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We are a team of fitness, health, and supplement experts, and content creators. Over the past 4 years, we have spent over 123,000 hours researching food supplements, meal shakes, weight loss, and healthy living. Our aim is to educate people about their effects, benefits, and how to achieve a maximum healthy lifestyle. Read more.