How To Take Phentermine 37.5 For Best Results


To help get all the essential nutrients that you might be missing on your diet, take some vitamins and supplements. Magnesium, chromium, biotin, and vitamins A, C, and E are highly recommended (6).

Phentermine Dosage

Medically reviewed by Last updated on Jul 22, 2022.

Applies to the following strengths: 30 mg; 15 mg; 37.5 mg; 8 mg; 18.75 mg; resin 15 mg; resin 30 mg

Usual Adult Dose for:

Additional dosage information:

  • Renal Dose Adjustments
  • Liver Dose Adjustments
  • Dose Adjustments
  • Precautions
  • Dialysis
  • Other Comments

Usual Adult Dose for Obesity

8 mg tablet (Lomira): 8 mg orally 3 times a day 30 minutes before meals

  • Some patients may only require 4 mg dose (one-half tablet) 3 times a day
  • Some patients may only require 18.75 mg (one-half tablet) orally once a day OR 18.75 mg orally twice a day
  • Dosage should be individualized to obtain an adequate response with the lowest effective dose.
  • Late evening dosing should be avoided due to the possibility of insomnia.

Renal Dose Adjustments

Mild to moderate renal impairment: No adjustment recommended
Severe renal impairment (eGFR 15 to 29 mL/min/1.73 m2): Maximum dose: 15 mg/day
ESRD (eGFR less than 15 mL/min/1.73 m2): Avoid use

Liver Dose Adjustments

No adjustment recommended

Dose Adjustments

Elderly: Dose selection should be cautious, usually starting at the low end of the
dosing range; consider monitoring renal function as this drug is substantially excreted by the kidney



  • History of cardiovascular disease (e.g., arrhythmias, congestive heart failure, coronary artery disease, uncontrolled hypertension, stroke)
  • Hypersensitivity or idiosyncratic reaction to sympathomimetic drugs
  • Hyperthyroidism
  • Agitated states
  • Glaucoma
  • History of drug abuse
  • Use of monoamine oxidase inhibitors concurrently, or within 14 days
  • Breastfeeding
  • Pregnancy

Consult WARNINGS section for additional precautions.

US Controlled Substance: Schedule IV


Other Comments

Administration Advice:

  • Take orally; avoid late evening administration due to the possibility of resulting insomnia
  • This drug is indicated for short-term use in a weight loss program based on exercise, behavioral modification, and caloric restriction.
  • The safety and efficacy of combination therapy with phentermine and any other drug products for weight loss have not been established; coadministration of drug products for weight loss is not recommended.
  • Tolerance to anorectant effect generally develops and if this occurs, this drug should be discontinued; the recommended dose should not be exceeded.
  • Monitor for development of tolerance
  • Consider monitoring renal function in elderly patients
  • Monitor for development of new, unexplained symptoms of dyspnea, angina pectoris, syncope, or lower extremity edema
  • Monitor for potential abuse
  • Patients should be informed about the risks of using this drug, potential adverse reactions, and when to contact their healthcare provider.
  • Patients should be instructed to avoid activities that require mental alertness such as driving and operating machinery until they know how this drug affects them.
  • Women who are considering becoming pregnant should speak with their healthcare provider; this drug should not be used by women who are pregnant or breastfeeding.

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Drug Status
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CSA Schedule* Some potential for abuse 4
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Pill K 25 is Phentermine Hydrochloride 37.5 mg

Phentermine systemic 37.5 mg (K 25)
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Subscribe to newsletters for the latest medication news, new drug approvals, alerts and updates. provides accurate and independent information on more than 24,000 prescription drugs, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. Data sources include IBM Watson Micromedex (updated 5 Feb 2023), Cerner Multum™ (updated 6 Feb 2023), ASHP (updated 11 Jan 2023) and others.

How to Take Phentermine For Best Results

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Being overweight can take a toll on your body. It may cause serious health conditions, which are more often related to the heart. The good news is that you can reduce your risks by taking small steps to be healthier and losing weight can get you started.

You must know all the necessary information to successfully use the drug, which includes dosage, timing, and other safe practices.

Are you ready to take on the challenge and make being healthy your new year’s resolution? We’ll help you! Read on to know more about the details.

What should you consider before taking Phentermine?

Before deciding to use any medication, the risks of taking the drug must be weighed against the benefit it will give. This is a decision that you and your doctor should discuss and make. For Phentermine, you have to note the following:

  • Have you ever had any allergic reactions to medicines? How about on food, dyes, and animals? If yes, tell your doctor.
  • Phentermine should not be given to kids age 16 and below as effectiveness and safety, especially in this age group, is not yet established (2).
  • No studies about the use of Phentermine have demonstrated problems among geriatrics. However, elderly patients are more likely to have heart, kidney, or liver problems, which need caution and dose adjustments (3).
  • Phentermine should not be used by pregnant women. Studies have shown positive evidence of fetal abnormalities (3).
  • Harmful infant effects were also noted in studies conducted among breastfeeding moms (3). If you really have to take this drug, you need to stop breastfeeding.
  • Do not take Phentermine if you are taking other medications like MAO inhibitors, Furazolidone, Iproniazid, Linezolid, and the like (3).

How to use Phentermine properly?

Phentermine should be taken exactly as directed by a medical professional. You must not consume more than what is prescribed. If you take too much of Phentermine, it may become a habit, causing drug dependence (4).

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Phentermine is available in four forms – capsule, tablets, disintegrating tablets, and extended-release capsules. Each one of this form has its own dosing instructions, which you can find the packaging labels.

Extended-release capsule and tablet forms must be taken as a whole. They should not be chewed or crushed (3).

The disintegrating tablet can be taken before or after a meal. Just be sure that your hands are well dried before getting a tablet. Place it on top of your tongue straight from the bottle. It will melt easily. Once completely melted, drink water (3).

Phentermine is a stimulant, hence best taken in the morning. It must not be taken 4-6 hours before bedtime unless instructed by your doctor. Late night medication can possibly cause insomnia (2).

What’s the right dosage of Phentermine for weight loss?

The dose of Phentermine may vary for different patients. It is a must to follow your physician’s orders. The average doses found on the drug label may not always be suitable for you. The doses you need to take every day, the time allowance in between doses, and the duration of intake will likewise depend on your medical condition.

Phentermine hydrochloride is an appetite suppressant commonly taken by people who would want to lose extra weight. The usual dosage may range from 15-37.5 mg (2).

Depending on which form of Phentermine are you using, dosage and time of intake may vary. To be more specific, here are the recommended dosages for adults age 17 and above:

  • Capsule dosage may range from 15-10 milligrams. It is taken once daily, approximately 2 hours before breakfast.
  • Disintegrating tablets are taken once a day, every morning, with or without food.
  • Extended-release capsules are also taken once a day before breakfast or on an average of 12 hours before bedtime.
  • Tablet dosage may range from 18.75-37.5 mg. This must be taken once in a day, before breakfast or 2 hours after.

What should you do if you missed a dose?

You may take a missed dose anytime as long as it is not near your next scheduled intake. Never double dose. Keep a good record of your drug intake and set an alarm if necessary to avoid missing a dose.

How to keep Phentermine properly?

Similar to other drugs, Phentermine must be safely kept in a dry, cool, and dark place. Do not store it in the bathroom to avoid warming and moisture. Be sure to keep it out of reach for kids.

While Phentermine is a proven weight loss medication, there are several tips and ways to maximize its effect to make sure that you’ll get the most out of your daily dose.

1. Know that Phentermine needs the right diet and exercise to work successfully

The effect of Phentermine may go on a plateau through time, and a lot of patients develop resistance to it. For these reasons, it is very important that you practice a sustainable diet and exercise plan while taking the drug. Phentermine can help you lose weight in the first few weeks, but only diet and exercise can maintain its wonderful effects (5).

Adding cardio and some weight-bearing exercises into your routine are the key to achieve rapid weight loss with this drug. Running and dancing can help boost your metabolism while toning exercises and weight lifting can tone your body and build lean muscles. Do these for around 10-15 minutes, at least 3x weekly to see the difference!

And even if Phentermine can suppress your appetite, it is very important for you to know that you still need to eat right to lose weight, especially because it’s only intended for short-term use, and can wear off or even stop working for you completely after a few months.

Generally, you must never go below 1,200 calories per day (5). You can discuss this with your doctor for a more personalized figure, considering your age, height, weight, and sex. Anything less than 1,200 calories daily may slow down your metabolism and your body will soon start to hold onto fat as fuel instead of burning it (5). You have to keep your metabolism running smoothly. You can take meals or snacks rich in protein and fiber. Fruits and vegetables are recommended too.

2. Drink Lots of Water

Drinking lots of water can help reduce weight by making sure that your body is at its best to support all important bodily functions like burning fats and boosting metabolism. Also, drinking water can make you feel full, satisfying your appetite minus the calories. You must take water consistently all throughout the day, but one glass at least 20 minutes before mealtime is recommended (6).

Keeping a steady supply of water can help you lose water weight. This can be noticed easily during the first week of taking Phentermine. If your diet is high in sodium, the body will hold onto the water to keep you hydrated. This adds up to the numbers in your scale.

Also, water can help relieve dry mouth, which is a common complaint among Phentermine users (6).

3. Keep an Alkaline pH

While drinking water and exercising are considered to be two of the most important ways to help you lose weight, keeping an alkaline urinary pH can also enhance Phentermine’s effects. Experiments published in Medical Toxicology 3rd edition in 2004, results showed that with an acidic urinary pH, 5.5-6.0, 84% of Phentermine dose is excreted unchanged by the kidneys in as fast as 24 hours (7). On the other hand, alkaline urinary pH, 7.5-8.0, only excreted 48%. Why is this important? For a drug to work well, it has to stay in the body for a longer period of time for metabolization. Without this, effects will not be visible.

There are several foods that can help you keep an alkaline pH, but testing is recommended as others may be allergic to them. Some of the best alkalizing foods include onions, carrots, tomatoes, cucumbers, apples, grapes, lemons, berries, bananas, cinnamon, and almonds (7).

You must avoid acidifying drinks and foods like coffee, alcohol, butter, and ice cream (7).

4. Establish A Healthy Lifestyle

Losing weight requires you to put your health first, which includes getting enough rest and sleep and drinking vitamins for additional support.

Sleep and rest can help you reduce stress. Your body becomes stronger if you are mentally and physically stable. This is important to be able to sustain weight loss and endure the activities that you are engaged in.

To help get all the essential nutrients that you might be missing on your diet, take some vitamins and supplements. Magnesium, chromium, biotin, and vitamins A, C, and E are highly recommended (6).

By taking Phentermine at the right time using the most appropriate dosage, you’ll surely make the most of this diet pill. With the additional tips and hints mentioned above, you can achieve your goal faster and even better. Again, for a good start, consult your doctor. Cheers to a healthier you!


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How To Take Phentermine 37.5 For Best Results [#New Guide 2023 Released]

Phentermine is an effective appetite suppressant and a popular weight loss drug approved in 1970, the chemical 2022 is available by the brand name Adipex and 100 others are prescribed by doctors for use.

Phentermine 37.5

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In 2022, people’s understanding of how to take phentermine 37.5 for best results has been taken seriously by medical experts who think using phentermine improperly can be fatal and may not lead to successful weight loss.

Millions of people in the world take Phentermine diet pills as a weight loss measure but not everyone got an idea about how to use it for the best results. Click Here to Buy Phentermine

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How to lose weight on phentermine fast is a real query which has been answered many times.

Phentermine 37.5 Reviews

Categorized in the list of potent stimulants, the phentermine pill is recommended to an obese individual diagnosed with type-2 diabetes or higher BMI.

Phentermine is an effective appetite suppressant and a popular weight loss drug approved in 1970, the chemical 2022 is available by the brand name Adipex and 100 others are prescribed by doctors for use.

Phentermine is not recommended for a long-time duration, this indicates the excessive use of this diet pill can be causing addiction, dependence, and psychological adverse reactions.

Phentermine is available in the following dosage forms which are only cycled as per the physician guidelines.

How Can I Increase My Phentermine Effectiveness?

A few phentermine users found the small doses ineffective as they didn’t get enough energy they expected.

Phentermine is not an energy booster, but it rather affects the appetite and sometimes it leads to an indirect surge of energy levels.

To increase the efficacy of Phentermine 37.5mg, here are a few ways to enhance it.

  • Exercise: Phentermine readily improves energy levels in users who are perpetual in physical workouts. While taking Phentermine 37.5, it is significantly advantageous to perform 4-5 times physical workouts in a week.
  • Healthy Diet Intake: Whatever you eat will directly affect the absorption or duration of action of the drug. Eating a diet high in acid with Phentermine 37.5 mg is deemed to render no useful effects. Edibles like ice cream, coffee, soda, or alcoholic beverages should be avoided. Try to design a dietary plan that involves as many nuts as possible, carrots, bananas, and berries in your diet.
  • Drink Water: Staying hydrated is one of the main factor phentermine users should keep in mind. Consuming 8-10 glasses of water every day is thought to be considerably beneficial for phentermine before and after results.

How Much Weight Should You Lose in a Week on Phentermine?

Phentermine users searched for the value of how much weight they are going to shed, depending on the weight loss goals, diet plan, and overall lifestyle, it’s possible that you may notice a few pounds reduction within 14 days.

Losing 1-2 pounds in the first week with Phentermine pills is normal and it ensures the lean mass stays without getting wasted.

Phentermine intake early in the morning leads to marked appetite suppression which works throughout the day.

How long do you take Phentermine Before You See Results?

Right after the first dose, phentermine starts to work and is absorbed through the GI tract instantly.

The peak plasma concentration of phentermine is achieved within 4.4 hours, after this time users will begin to see the effects of appetite suppression and tolerance against binge-eating.

Once again, Phentermine’s prolonged use could also lead to tolerance built by the body, in which case a proper consultation by the doctor is required.

When is the Best Time to Take Phentermine?

Taking Phentermine at a right time is very important because it should be the same the very next day.

According to the recommendation by the experts, Phentermine is taken on an empty stomach before breakfast, you can break it in two pieces, but it’s not allowed to crush or chew it.

Phentermine is an anorectic drug as well as a stimulant that may disturb the sleep cycle.

The diet pill is not advised to take during the daytime, even if the doctor has prescribed you two times phentermine pills daily, make sure to take the other one 6-7 hours before sleeping.

What Should You Not Eat When Taking Phentermine?

Here is the list of foods to avoid while taking phentermine.

Acidifying Food

Foods that are high in acid may interrupt the metabolism and excretion of phentermine drugs. Studies show intake of acidifying food leads to the faster excretion of Phentermine metabolites and thereby lowering its effects.

Remember, it’s not recommended to have soda drinks, sugar, butter, and food products with white flour.


Sugary foods are the reason for weight gain in millions of people in the world. Edibles like donuts, soda, and ice cream may taste delicious but they also deter the phentermine mechanism. It will be very difficult to have control over sugar cravings if you are taking sugar-containing food with phentermine.

Refined and Simple Carbs

Not just sugar, but carbohydrates are the main thing to avoid while using phentermine. Both refined and simple carbs accumulate in the body in a form of fat tissues which also display high blood sugar levels.

You will find the doctor asking you not to take the following things if he/she prescribed you phentermine.

  • Chocolates
  • Jam n Jellies
  • Candies
  • Soda
  • Pasta
  • Packaged Cereals
  • Cookies
  • White bread

Processed Food

Going easy on your diet is mandatory with phentermine; certain junk foods and processed meat are still being sold which are too bad for your health.

These unhealthy junk and processed food contain trans fats which makes you rapidly gain weight and phentermine sheds it. Research shows processed food is linked to obesity and users must take countermeasures before taking phentermine.

Processed and junk foods listed below should be completely avoided.

  • French fried/potato chips
  • Fast food meals i.e. KFC, McDonald, Wendy’s
  • Processed Meat i.e., Salami, Sausages, Bacon, Canned meat, and Corned Beef


Phentermine and alcohol do not go so well and that’s why you shouldn’t be drinking them. A combination of phentermine 37.5 mg and alcohol could lead to chest pain, high blood pressure, and other health calamities which can also lead to death.

Is it Better to take Phentermine on an Empty Stomach?

If you have been prescribed Phentermine Disintegrating tablets, adults should take it three times daily 30 minutes before a meal.

Three times daily intake of phentermine is only allowed if you’re given Phentermine 8mg.

However, if you are using 15-37.5 mg Phentermine dosage, only a single capsule is enough for the day, but it should be taken on an empty stomach as well as in the morning.

Can I Drink Caffeine While Taking Phentermine?

Combining two stimulants Phentermine and Caffeine could lead to increased heart rate, insomnia, and jitteriness.

The side effects of phentermine are further elevated when you put caffeine with it. Always limit your caffeine intake while running the phentermine cycle for weight loss.

How Do I know if Phentermine is working?

Do not be hasty when it comes to phentermine results, since the drug takes around 4.4 hours to reach the peak plasma concentration. But the results may vary depending on the previous body mass index, exercise routine and dietary habits.

If users manage to minimize the consumption of sugar, carbs, and trans food, it might take them 7-10 days to see the initial weight loss result.

How Fast Can I lose Weight on Phentermine?

Phentermine before and after results explained by the real-time users, a typical 3% of body weight reduction is achieved after 3 months.

Phentermine 37.5 continuous use for 6 months could reduce 5-7% body weight, while some people witnessed more value than this.

A person who weighed around 200 pounds, he/she could lose 10-14 pounds with phentermine within 90 days time frame.

However, using phentermine for more than 3 months is deemed risky to the health and other body functions, and that’s why many physicians do not recommend it for a prolonged period.

Should You Take Phentermine 37.5 mg Twice a Day?

Generally, Phentermine 37.5 mg capsule is taken once daily, but it can also be divided into two dosage forms (one in the morning and one at night).

The recent brand name of Phentermine (Lomaira) is available in 8mg dosage forms which can be taken up to three times daily.

How to Intensify Phentermine?

Phentermine weight loss plan can be hugely supported by Cardio and Weightlifting.

Cardio exercises help the body to stay in shape while weightlifting makes sure you don’t lose lean muscle mass.

Lean mass tends to scatter away if you take phentermine without physical activity.

Some people make the common mistake of taking Phentermine 37.5 mg multiple times a day which is not good for their health. Instead of intensifying the phentermine mechanism of action, this might exacerbate the side effects of phentermine.

Can You Take Phentermine Every Other Day and Still Lose Weight?

It’s not a good idea to keep on using phentermine and expect to lose body weight consistently. Some people take double dosages of phentermine, but this practice is limited to 7 days only.

Using Phentermine without intermittent fasting or other lifestyle changes is not worth using. The best way to use it is early in the morning when it helps to reduce the appetite throughout the day.

How to Take Phentermine Explained – Bottom Line

Some people spent years using phentermine used for weight loss and lost only a small fraction of body weight, while others only run a 3-month cycle and got amazing changes.

Phentermine is an FDA-approved drug that is not natural and might evoke some shocking side effects if you are new to this drug.

Standard protocols must be applied by the doctors like checking on the patient history, allergic conditions, and cardiovascular event occurrence in which the Phentermine pill is contraindicated.

Never use Phentermine solo but in conjunction with a doctor’s recommendation and guideline.

Otherwise, you may end up damaging your metabolic health and other noteworthy body functions.

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Alex Koliada, PhD

Alex Koliada, PhD, is a well-known doctor. He is famous for his studies of ageing, genetics and other medical conditions. He works at the Institute of Food Biotechnology and Genomics NAS of Ukraine. His scientific researches are printed by the most reputable international magazines. Some of his works are: Differences in the gut Firmicutes to Bacteroidetes ratio across age groups in healthy Ukrainian population []; Mating status affects Drosophila lifespan, metabolism and antioxidant system [Science Direct]; Anise Hyssop Agastache foeniculum Increases Lifespan, Stress Resistance, and Metabolism by Affecting Free Radical Processes in Drosophila [Frontiersin].
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