Clenbuterol vs Phentermine: Best Taken Together or Separately?

January 9, 2024 |

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Looking to lose weight quickly and safely? You may be considering using prescription weight loss drugs like phentermine or Clenbuterol.

But which is the better option for you?

Phentermine is an FDA-approved appetite suppressant, while Clenbuterol is an adrenergic agonist that helps burn fats and grow lean muscles, but it is not approved for human use due to its steroid-resembling properties.

To help you find out which one is more effective for weight loss and how these two stimulants affect your health, we jotted down a side-by-side comparison of their benefits and side effects.

Further, we have added a short segment to review safe, stimulant-free alternatives to these drugs.

So, stay tuned to know whether Phen or Clen is a better option for weight loss.

Clen vs Phentermine – Table Comparison

Criteria Clenbuterol Phentermine
Type: Adrenergic agonist Appetite-suppressant
FDA Approval: Not approved for human use FDA-approved
Weight Loss Effect: Rapid fat loss and increased metabolism Appetite suppression and a slight boost in metabolism
Muscle Growth Effect: Increased skeletal muscle strength, endurance, and size No such effect
Common Side Effects: Muscular tremors, irregular heartbeat, anxiety, chest pain, sweating, sleep disturbances, nausea, and headaches Dry mouth, increased heart rate, anxiety, disturbed gut, and sleeplessness
Long-term Side Effects: Increased muscle fatigability and deformities in addition to muscle growth Risk factors for pulmonary hypertension, ventricular fibrillation, heart arrhythmias, and valvular diseases
User Reviews: Effective for weight loss but may cause tremors and jittery feelings Effective for weight loss and increased energy with positive reviews from users
Cost: Only available for veterinary use $16.44 to $23.35 for a 30-tablet pack of 37.5mg Phentermine HCL
Safer Alternative: CrazyBulk’s Clenbutrol (see here) PhenQ (see here)

Phentermine vs. Clenbuterol – Exploring Both Compounds

Phentermine is basically a sympathomimetic methylated amine; it has amphetamine-like properties and stimulates the central nervous system, suppressing the appetite.

It increases dopamine concentration in the brain and norepinephrine in the blood, which induces a sensation of fullness and lack of hunger.

In contrast, Clenbuterol is an aniline having beta-2 adrenomimetic properties. Though not a steroid by definition, this β-2 adrenergic agonist (commonly called β2 agonist) acts very similar to anabolic steroids.

It induces dilation in smooth muscles, which helps dilate bronchial passages in asthmatic persons.

That is why it is sometimes prescribed to treat asthma and chronic obstructive pulmonary disease (COPD).

However, it also increases lean muscle growth and speeds up fat loss. Hence, many bodybuilders use it for bulking and cutting purposes.

Nevertheless, it is a potent stimulator and may cause adverse effects, which is a reason for disapproval of its usage for humans.

Additionally, it is included in the prohibited substances list of the World Anti-Doping Agency (WADA) as it induces a sudden burst of strength and muscular activity.

Phentermine and Clenbuterol – Benefits

Phentermine benefits

Phentermine is indeed a very effective appetite suppressant.

Phentermine formula

After taking this pill, you will not feel the hunger pangs or food cravings that make most diets fail.

Plus, the dopamine surge induced by this sympathomimetic drug will make you happier and more energetic. This is because dopamine is associated with the feeling of reward, gratification, and pleasure.

Another benefit you get from phentermine is a slight boost in metabolic rates. Phentermine is known to increase resting energy expenditure as it tends to increase heat production (thermogenesis) in the body.

Bulleted benefits of phentermine include:

  • Increased energy and motivation
  • Suppressed appetite, can lead to weight loss
  • Improved mood and decreased anxiety
  • Increased focus and productivity
  • Better sleep quality

Clenbuterol benefits

On the other hand, Clenbuterol is used for weight loss mainly due to its ability to increase metabolic speed, resulting in fat burn.

Compared to phentermine, which only has mild thermogenic properties, Clen-induced thermogenesis is significant and results in rapid fat loss.

Clenbuterol chemical structure

Moreover, research shows that high doses of Clenbuterol activate lipid-dissolving enzymes. Eventually, fat metabolism speeds up.

As Clenbuterol influences adrenergic secretions (resultantly raising blood levels of stress hormones), it also suppresses hunger sensation.

But this is the secondary effect of Clen, and some users say that they do not feel any difference in their appetite.

The primary benefit that makes Clen popular in the bodybuilding subculture is its ability to increase skeletal muscles’ strength, endurance, and size.

In contrast, phentermine shows no such effects.

Research shows that secretion of growth hormone and protein synthesis in skeletal muscles is increased by Clenbuterol treatment. Plus, it is known to have a rapid, inhibitory effect on protein degradation.

Benefits of Clenbuterol include:

  • Increased muscle mass
  • Improved endurance
  • Reduced body fat
  • Increased strength
  • Faster metabolism
  • Better cardio performance
  • Improved breathing

Safety of Clen of Phentermine

How safe is Phentermine?

Phentermine is generally a safe drug because most users can tolerate its common side effects. Its safety is also confirmed by scientific evidence, due to which FDA has approved its usage for weight loss purposes.

However, as a nervous system stimulator, phentermine is also associated with side effects.

Due to this reason, FDA approves it only for short-term usage. The most common of these are dry mouth, increased heart rate, anxiety, disturbed gut, and sleeplessness.

However, if taken for a long duration or overdosed, phentermine may cause severe cardiac, brain, or mental health issues.

High doses, it is a risk factor for pulmonary hypertension. Likewise, cases of ventricular fibrillation, heart arrhythmias, and valvular diseases are reported by long-term phentermine users.

Furthermore, it is found to be associated with brain injuries in rare cases.

How safe is Clenbuterol?

On the other side, Clenbuterol is not approved for humans in the United States for either pulmonary diseases or bodybuilding purposes.

Research shows that Clen usage is not a win-win solution for muscular health because long-term treatment increases muscle fatigability and deformities in addition to muscle growth.

At low doses, Clenbuterol may cause muscular tremors, irregular heartbeat, anxiety, chest pain, sweating, sleep disturbances, nausea, and headaches.

When overdosed, its adrenergic effects are associated with relatively severe side effects compared with phentermine.

Many myocardial injuries and heart attacks have been reported by using Clenbuterol in higher quantities, taking it with other steroids, or using it for a long time.

A 22-year-old bodybuilder was diagnosed with myocarditis because he used Clenbuterol to build muscles and strength.

Another severe incident was reported from a 61-year-old man who was taking Clen with other anabolic steroids.

He suffered from cardiac arrest at midnight and unfortunately died from the severity of the attack.

Clenbuterol was found in all his tissues as he had been using the drug for a long time which possibly caused his death.

User reviews of Phentermine and Clenbuterol

Phentermine reviews

Phentermine is an approved drug that has been quite famous for weight loss for decades. Thousands of people have tried it and shared their experiences with the anorectic.

Different Rx platforms enlist several user reviews from phentermine users.

On, 84% of the people who reviewed phentermine HCL rated their experience with this drug as positive.

Phentermine user reviews on Drugs

While 5% of people said they had a bad experience.

Clenbuterol reviews

On the other side, pharmacology platforms do not list Clenbuterol reviews as Clen is illegal for human use.

However, you find many user experiences people have shared through social media sites.

Many of them find Clenbuterol very effective for weight loss but also mentioned the tremors and jittery feelings after taking the dosage.

A person mentioned that he had to stop Clen’s use because he felt too shaky under its influence.

Another user told his experience with the drug like this “I took only 0.015mg (half tablet), had crazy muscle shakes, and my resting heart rate sat around 100–110.”

Phentertime vs Clenbuterol – Cost

Phentermine cost

You can buy phentermine in capsule (15mg, 30mg, 37.5mg) and tablet (37.5mg) forms.

Usually, you will get 30 tablets packing of 37.5mg phentermine HCL for $16.44 to $23.35 from a local or online pharmacy on prescription.

Clenbuterol Cost

You cannot get a prescription for Clenbuterol if you live in the U.S.

Instead, it is only available for veterinary use. Usually, it comes as an oral solution (Ventipulmin Syrup).

However, you may get this drug outside the United States because it is approved for treating bronchial congestion in some countries. The price range starts from $18 for 20 tablets of 0.02 mg.

Also, read:

What is Safer and Better than Phentermine & Clenbuterol?

There are a few different products that are safer and better than Phentermine and Clenbuterol.

Asides their side effects – you can only get them in a few selected countries. With strict prescriptions.

PhenQ appetite suppressant is one such product, as it is made with all-natural ingredients and does not cause the negative side effects associated with prescription diet pills. Another good option that replaces Clen is Clenbutrol by CrazyBulk, which has been shown to be both safe and effective in helping people lose weight.

Let’s dive deeper into both:

PhenQ (Phentermine)


PhenQ is a safe alternative to phentermine.

This is an over-the-counter product because none of its ingredients is harmful to your health.

The only stimulant it contains is caffeine anhydrous, whose quantity is so minor that its negative stimulatory effects are rarely visible. However, it does have the potential to boost your energy level and balance your mood.

Another characteristic that makes phenQ more effective and safer than phentermine is how it curbs your appetite.

It reduces the secretion of ghrelin (hunger hormone) instead of increasing stress hormones in the bloodstream (which ultimately brings the disadvantages of depression and anxiety).

PhenQ will give you the benefits of both phentermine and Clenbuterol because it also increases day metabolism in your body and reduces the production of new fat compounds in tissues.

Thus, if your goal is to lose weight and burn fats, but you struggle with binge eating, PhenQ is the right diet supplement for you.

P.S. It’s an entirely plant-based product, so you do not need to worry if you only take vegan supplements.

Crazy Bulk’s Clenbutrol (Clenbuterol)



If you want to lose fat but grow muscular as well. Clenbutrol from Crazy Bulk can prove to be your savior.

It is a risk-free alternative to Clenbuterol that provides enormous fat loss without putting you at risk of severe cardiovascular diseases. The reason is its vegan formulation which includes natural fat burners and growth-inducing substances.

The best thing is it is an over-the-counter product that you can also use as a pre-workout.

Its key ingredients are Niacinamide (vitamin B), Garcinia Cambogia, Bitter Orange Extract (Synephrine), Guarana Extract, and Microcrystalline Cellulose.

Garcinia Cambogia is a tropical fruit whose extracts are added to this diet supplement to suppress unlimited appetite and food cravings.

As proven by research, Garcinia compounds also prevent fat accumulation in the body.

Similar hunger-reducing effects are provided by Synephrine (the active ingredient in bitter orange extracts).

Fat-burning properties are credited to thermogenesis induced by Guarana extracts and vitamin B.

Niacin in it is a miracle compound that helps reduce food cravings, increases metabolic rate, and slows down muscle protein degradation. That is why you will find it in most pre-workouts and weight loss supplements.

All in all, Crazy Bulk’s Clenbutrol is a better choice to build up strength and maintain a lean body figure than the adrenergic stimulator- Clenbuterol.

Clen CTA


What is the safest clenbuterol dosage for weight loss?

120 mcg to 140 mcg is the highest daily dose considered safe when losing weight on Clenbuterol.

The Clen dose is usually taken in “cutting cycles” for fat loss, starting from 20 mcg daily and gradually raising the dose to 140 mcg daily.

Can you take phentermine and Clenbuterol at the same time?

No, it can be risky to simultaneously take two stimulants like phentermine and Clenbuterol.

Both these compounds result in the production of androgenic hormones, which raise blood pressure, heart rate and make your heart work harder.

Hence, if you take them together, there are chances your cardiac system would be hyper-stimulated, resulting in serious cardiovascular problems.

What are common clenbuterol side effects?

Common side effects of Clenbuterol include palpitations, Tremors, Anxiety, chest pain, electrolyte imbalance, sweating, and headaches.

How much weight will you lose on Clenbuterol?

Generally, people lose from 2 to 4 pounds in a week with Clenbuterol.

Final Thoughts

Phentermine and Clenbuterol both result in quick weight loss then you may achieve alone from a diet and workout regime. However, phentermine is relatively safer and FDA-approved, but Clenbuterol is potentially more dangerous.

Plus, it is only approved for veterinary use in the USA and is included in the prohibited substance list of the World anti-doping agency.

Resultantly, Clenbuterol usage comes with a risk of severe cardiovascular problems and can get you out of the competition through a positive dope test.

So, whether you are a fitness freak wanting to burn fats and maintain a lean body figure or a professional athlete looking to enhance strength and performance, the best suggestion is to opt for over-the-counter options that give results but don’t compromise on health safety.

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