How to Use Phentermine?

Knowing how to take Phentermine is an important part of a successful weight loss campaign.

We will explain how to use Phentermine correctly to get the best of it and bust myths about the duration of treatment, and many more.

Read on to learn more about proper use of Phentermine, its long-term use and what are signs that you are abusing the drug.

Bonus tip!
Start Phentermine use on your weekend or on days, when you don’t need to drive or work.
Thus, you will check out your body response to the drug and avoid possible unpleasant events.

How to use Phentermine properly

The easiest way to find out general recommendations on Phentermine use is to check out the leaflet of the drug.

General… right. They’re not wrong, yet some people might need adjustments.

But first things first.

Promised answers to 5 most frequent questions in “How to take Phentermine correctly” section.

Answer no.1: How overweight you should be to use Phentermine?

Simple! You should be out of the healthy weight range (namely above its upper limit).

What does it mean?

  • Being in the overweight/obese category according to the BMI chart.


  • Having a waist circumference, longer than recommended


If your weight is within the healthy range, you should not take Phentermine!

The drug is strong and should be used in extreme cases only.

Answer no.2: What dose of Phentermine should I take?

Everything depends on your individual peculiarities and body response to Phentermine effect.

If your doctor told you to take one pill of Phentermine 37.5 mg – take one pill.

If he tells you to split the pill and take half (18.75 mg) once or twice a day – do so.

If you take the 8mg pills, and you were told to take 1 before each of 3 main meals – right, just do so.



If you feel unwell or feel no effect, it is a good reason for asking your doctor to reconsider your daily dose of Phentermine.

Answer no.3: When should I take Phentermine?

General recommendation… again, yes.

Well, the general recommendation is to take Phentermine as early in the morning as possible.

risk of insomnia

Oh c’mon! Act wisely!

If you work night shifts, it is completely unwise to take Phentermine early in the morning, as it might disturb your daytime sleep (which is, obviously, the only one you can afford).

So, the best thing is to adjust the drug administration according to your usual sleep-awake schedule.


For those, who take the 8mg Phentermine pills, it is common to take Phentermine three times a day.

dosing regimen
* PO- orally
**TID – 3 times a day

Make sure that you observe the required interval between the last dosing and bedtime.

If you’re late, better skip the pill.

We don’t need sleepless nights, when we are trying to lose weight, do we?

Answer no.4: Should I take Phentermine on an empty stomach?

No! It is not an obligatory requirement.

with or without food

Using Phentermine successfully means that you are using it for as long as recommended and follow a proper slimming program.

Can you do it, if you feel nauseous and vomit all day long?

Obviously, you can’t.

The above mentioned reactions are pretty common in people, taking these diet pills on an empty stomach.

So, if you feel stomach cramps or nausea, or any other unpleasant upper GI tract manifestations, have your pill with a couple of teaspoons of yogurt/porridge, or half an egg.

Choose something to calm down your stomach and let you observe the developed eating plan.

Answer no.5: How long can I take Phentermine?

General recommendations… here we go again. These can be adjusted, as you know.

Of course, most doctors will tell you not to exceed the 12-week period.

And it’s good, since it’s the manufacturer’s recommendations, based on the results of clinical trials.

duration of use

But read on to see the promised MYTH BUSTING about the duration of its use.

If you feel that Phentermine is not working and none of possible solutions to bring the effects back work for you, means it’s high time to stop taking it.

It’s a pity, your body developed tolerance to the drug.

Tip of the day!

If you develop tolerance, Phentermine might not work for you next time.

Better ask your doctor for a 4-pill trial pack to make sure that your body does react and it is reasonable to buy the entire Phentermine pack.

Now to the MYTH BUSTING part!

Long-term use of Phentermine


You can take Phentermine-containing pills longer than 12 weeks!


You do need to take a break from their use for the sake of your own health and to stop the development of tolerance to the drug action.

That’s not all.

You might have heard or read about clinical trials on Phentermine that lasted for 14 weeks.

The results were great, that’s right.

Phentermine 14 weeks



The two extra weeks were the placebo run-in weeks, which means that no treatment was given to patients.

So don’t let anyone confuse you. Because now you know!

Of course, following your doctor’s recommendations is without a doubt the smartest thing you can do (if your doctor is a real professional, that is).

Phentermine abuse

Moving on to a serious issue – the drug abuse.

The instructions for Phentermine use include a warning about a high potential for this drug abuse.

Phentermine abuse


However, clinical trials, even really long-lasting ones, have proven these assumptions to be wrong when it comes to Phentermine.

long term tretment


Phentermine recreational use

Never heard of Phentermine being used as a party drug?

Good on you! Some people have.

Their decision on taking Phentermine to get high is backed up usually by two notions:

  • Phentermine has a formula similar to amphetamine
  • People get euphoria when they use this drug

Well, the first notion is true.

But check again the above extract of a trial.

It proves Phentermine to cause no amphetamine-like withdrawal, hence no such “positive” effects either.

The second notion is also true.

However, the so called “euphoria” is a side effects of Phentermine, and not every person gets this side effect!

Besides, this drug is strong and can cause quite serious adverse reactions.

So it’s definitely a poor candidate for recreational use.

Use ONLY as directed by a competent doctor and pair with a proper weight loss program to get the best results with Phentermine!

If you have an interesting story to share about your way of using Phentermine or have any questions that are not covered in this article, feel free to comment and share.