Average Weight Loss on Phentermine - Phentermine.com (2022)

Average monthly weight loss on phentermine is not a precise figure because weight loss varies so significantly from person-to-person. While some patients lose 20 or more pounds in a single month, others struggle to drop even one pound per week. Starting weight, pre-existing medical conditions, genetics, diet, physical activity and other factors all affect individual phentermine weight loss results.

Still, despite the wide range of actual phentermine results (and reviews), most people lose more weight with phentermine than without it.

How Phentermine Enhances Weight Loss

Average Weight Loss on Phentermine - Phentermine.com (1)

Phentermine is a central nervous system stimulant. It creates a biological response similar to “fight or flight” that promotes weight loss because, as part of the heightened state, appetite decreases, energy increases and metabolism revs ( 1 ). All of these effects work together to help patients lose weight faster and easier.

Average Weight Loss on Phentermine - Phentermine.com (2)
Average Weight Loss on Phentermine - Phentermine.com (3)

Still, phentermine is not a miracle pill. It should always be combined with healthy lifestyle changes to achieve best results.

How Much Weight Can I Expect to Lose on Phentermine?

Minimum expected weight loss on phentermine is ≥5% of body weight in three months ( 2 ).

This translates to a predicted weight loss of at least 10 pounds for someone with a starting weight of 200 pounds, or at least 12.5 pounds for a person who starts at 250 pounds.

Here are the short-term weight loss goals for patients at different starting weights:

(Video) HOW MUCH WEIGHT HAVE I LOST ON PHENTERMINE|| IS IT WORTH TAKING||

Starting Weight (lbs)Short-Term Goal (-5%)Pounds to Lose
1401337
1601528
1801719
20019010
22020911
24022812
26024713
28026614
30028515

While these modest weight loss goals may seem disappointing to some more-ambitious dieters, it is healthier (and more sustainable) to lose weight slowly and steadily ( 3 ). Rapid, dramatic weight loss may be rewarding short-term, but it is much harder to maintain and puts you at an increased risk for lean muscle loss and nutritional deficiencies.

Unfortunately, the short-term nature of this medication makes many patients feel like they need to lose as much weight as possible, as quickly as possible.

Phentermine is only FDA-approved as a “short-term treatment” for exogenous obesity, meaning that it should not be taken for more than 12 weeks at a time ( 4 , 5 ). However, if someone has more weight to lose than proves realistic in 12 weeks’ time, many doctors will prescribe phentermine off-label for longer periods of time or give patients multiple rounds of treatment punctuated by 1-2 month breaks.

Phentermine Average Weight Loss

Every patient loses a different amount of weight, and loses weight at a different rate, while taking this medication. However, clinical trials and years of patients’ self-reported results give us a good idea about the average weight loss while taking phentermine.

Below you will find the latest information about average weight loss on phentermine in a week, month, three months, six months and one year.

In One Week

Average weight loss per week on phentermine is about 1-4 pounds, based on both clinical research and user reviews. Studies indicate weekly weight loss trends towards the lower end of this range, while patients self-report more rapid weight loss.

Average Weight Loss on Phentermine - Phentermine.com (4)

How much weight is that?
A 15 oz can of beans weighs about one pound.

In One Month

Weight loss varies significantly between individuals, but research shows that phentermine users can expect to lose about 3-5 pounds per month [6-8]. This is a healthy rate of weight loss that allows the body to burn fat while also maintaining valuable lean muscle tissue ( 5 ).

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(Video) HOW MUCH WEIGHT WILL I LOSE ON PHENTERMINE?

Still, users’ self-reports indicate that average weight loss on phentermine in a month is closer to 5-10 pounds, or even more (6). Younger, heavier and more active patients tend to lose weight faster than their older, lighter or more sedentary counterparts.

Average Weight Loss on Phentermine - Phentermine.com (5)

How much weight is that?
One standard bag of potatoes weighs about 4 pounds.

Notably, average weight loss in the first month of phentermine use is morethan weight loss in subsequent months for two main reasons:

  • Stronger stimulant effects. Patients often experience the strongest appetite suppression and most noticeable energy boost in the first couple of weeks of treatment, both of which facilitate greater weight loss.
  • Loss of water weight. People commonly drop pounds faster in the first month of a diet because they lose water weight when their bodies start drawing on glycogen for fuel ( 7 ).

Can You Lose 20 Pounds in a Month on Phentermine? ​

Yes, it is possible to lose 20 pounds a month on phentermine, but the average user does not achieve this striking weight loss.

Average Weight Loss on Phentermine - Phentermine.com (6)

Individuals that report rapid, dramatic weight loss are usually in their first month of treatment and have committed to major lifestyle changes alongside the medication. Sarah, for example, focused on healthy eating, proper hydration and regular activity during her postpartum phentermine journey. She lost an impressive 22 pounds in just one month!

(Video) Phentermine Weight Loss Journey | 2 Week Update

Read Sarah’s story and watch her video here.

In Three Months

In one study, patients who took 37.5 mg of phentermine HCL and followed a 1500 calorie per day diet lost an average of 16 pounds in 3.5 months. That equates to just under 5 pounds per month ( 8 ).

Another study found that taking phentermine hydrochloride alone, without any special diet or exercise plan, led to an average weight loss of 8 pounds in 3 months, or about 2.67 pounds per month. However, in this second study, results proved inconsistent with some patients losing no weight at all and others (especially younger subjects) losing more than 16 pounds ( 9 ).

Average Weight Loss on Phentermine - Phentermine.com (7)

How much weight is that?
A gallon of milk weighs about 8.6 pounds.

In Six Months

Users who have taken phentermine off-label for six months of continuous treatment, or who have been prescribed two separate rounds of phentermine with a break in-between, self-report an average weight loss of 55 pounds (10). When broken-down, that is an average loss of just over nine ;pounds per month.

Average Weight Loss on Phentermine - Phentermine.com (8)

How much weight is that?
5 medium-sized bowling balls weigh about 50 pounds.

In One Year

In a 1968 study, patients treated with 30mg phentermine resin (Duromine) plus a low-calorie diet lost an average of 27 pounds in nine months ( 11 ). That converts to about three pounds per month, or about 36 pounds per year.

However, based on more recent phentermine before and after stories submitted online, the self-reported average phentermine weight loss in one year is closer to 65 pounds, or a little over 5 pounds per month (10).

Average Weight Loss on Phentermine - Phentermine.com (9)

How much weight is that?
The average car tire weighs 22 pounds.

Qsymia: Average Weight Loss

Qsymia, a brand name combination of phentermine HCL and topiramate-ER, is one of the most effective weight loss medications on the market ( 12 ).

A 2012 study found that patients who took the highest dose of phentermine-topiramate (15 mg phentermine HCL + 92 mg topiramate-ER daily) lost significantly more weight than those who took a lower dose of phentermine-topiramate or a placebo. In fact, subjects taking the highest dose of phentermine-topiramate lost almost 11% of their starting body weight over the course of the 56-week trial (as compared to 5% and 1.5% in the lower dose and placebo groups, respectively). Given that the starting weight in this group was an average of 253 pounds, that translates to an almost 28-pound weight loss in just one year ( 13 ).

A subsequent study in 2016 supported these results, reporting that over 75% of patients on combined phentermine and topiramate treatment lost at least 5% of their body weight during the one-year trial period ( 12 ).

(Video) Phentermine for Weight Loss - 30 Day Results

  • Back to Phentermine Reviews and Results

References

  1. National Center for Biotechnology Information. PubChem Compound Database: CID=4771 (Phentermine).
  2. Apovian, C. M., Aronne, L. J., Bessesen, D. H., McDonnell, M. E., Murad, M. H., Pagatto, U., . . . Still, C. D. (2015). Pharmacological Management of Obesity: An Endocrine Society Clinical Practice Guideline.The Journal of Clinical Endocrinology & Metabolism,100(2), 342-362. doi:10.1210/jc.2015-1782
  3. Division of Nutrition, Physical Activity, and Obesity, National Center for Chronic Disease Prevention and Health Promotion. (2018, February 13). Losing Weight | Healthy Weight | CDC.
  4. Buchwald, H., Cowan, G. S., & Pories, W. J. (2007). Surgical management of obesity. Philadelphia, PA: Elsevier.
  5. U.S. Food and Drug Administration. (2012). Adipex-P (phentermine hydrochloride) capsules label [Brochure].
  6. Phentermine User Reviews for Weight Loss at Drugs.com. (2019, April 18).
  7. Mayo Clinic Staff. (2018, February 06). Weight loss stalled? Move past the plateau.
  8. Kim, K. K., Cho, H., Kang, H., Youn, B., & Lee, K. (2006). Effects on Weight Reduction and Safety of Short-Term Phentermine Administration in Korean Obese People.Yonsei Medical Journal, 47(5), 614. doi:10.3349/ymj.2006.47.5.614
  9. Kim, H. O., Lee, J. A., Suh, H. W., Kim, Y. S., Kim, B. S., Ahn, E. S., . . . Park, Y. G. (2013). Postmarketing Surveillance Study of the Efficacy and Safety of Phentermine in Patients with Obesity.Korean Journal of Family Medicine, 34(5), 298. doi:10.4082/kjfm.2013.34.5.298
  10. Various users. (2018, August 23). Phentermine Success Stories at Phentermine.com.
  11. Munro, J. F., Maccuish, A. C., Wilson, E. M., & Duncan, L. J. (1968). Comparison of continuous and intermittent anorectic therapy in obesity.British Medical Journal, 1(5588), 352-354. doi:10.1136/bmj.1.5588.352
  12. Khera, R., Murad, M. H., Chandar, A. K., Dulai, P. S., Wang, Z., Prokop, L. J., . . . Singh, S. (2016). Association of Pharmacological Treatments for Obesity With Weight Loss and Adverse Events.JAMA, 315(22), 2424. doi:10.1001/jama.2016.7602
  13. Allison, D. B., Gadde, K. M., Garvey, W. T., Peterson, C. A., Schwiers, M. L., Najarian, T., . . . Day, W. W. (2011). Controlled-Release Phentermine/Topiramate in Severely Obese Adults: A Randomized Controlled Trial (EQUIP).Obesity, 20(2), 330-342. doi:10.1038/oby.2011.330

FAQs

How much does the average person lose on phentermine? ›

The average weight loss when taking phentermine is 3% of your initial body weight after 3 months and 5–7% after 6 months. Some people report even more weight loss than this ( 5 , 6 , 9 , 10 ).

How much weight should I lose in a month on phentermine? ›

Based on these three studies, you can expect to lose roughly 3 to 6 lbs. per month, if you are a woman, and 5 to 8 lbs. per month, if you are a man, using a combination of phentermine and a low-calorie diet.

How many pounds a week can you lose on phentermine? ›

Depending on your lifestyle and the changes you make once you start, it's possible to lose several pounds the first week as your body sheds water weight. That being said, the recommended weekly rate of weight loss is one to two pounds. Losing weight slowly and steadily ensures your body is losing fat and not muscle.

How much weight can you lose in 2 months on phentermine? ›

You can really only use it for 2-3 months at a time at which point you need to give your body a break. Yes, you may lose 5-15 pounds during the 2-3 months that you take Phentermine but that weight will come back 99% of the time within another 3-6 months.

How can I make phentermine work more effective? ›

To really succeed with phentermine and lose weight fast your body needs to be healthy. This means getting enough sleep, eating right, exercising, and remembering to relax and de-stress. Most people don't realize how important sleep is. Sleep can not only help you reduce stress but also can really help with weight loss.

How do you know if phentermine is working? ›

It reaches peak concentrations in the blood in three to 4.4 hours. 3 This means that the effects of phentermine should kick in by this time, alerting you that the drug is working. Short-term effects of Adipex can include: Decreased appetite.

How long does it take to start losing weight on phentermine? ›

The bottom line is that phentermine works in just three to 4.4 hours. However, it may take a couple of weeks before you start to notice that you're losing weight. To see your results as quickly as possible, you should try to minimize your consumption of carbohydrates, stay hydrated, and stay as active as possible.

Why does phentermine work so well? ›

It works by activating your sympathetic (“fight or flight”) nervous system, so it's called a “sympathomimetic” drug or “stimulant.” Phentermine may help lower your appetite, so people who take phentermine tend to eat less.

How many calories should you eat on phentermine? ›

We recommend that you accompany the phentermine with a 1500-calorie diet with 20-25 grams of fat per day. We have American Diabetes Association diets to help you plan your meals – or you may prefer to use Weight Waters or NutriSystem meals. Exercise is an important part of the diet regimen.

Does phentermine speed up your metabolism? ›

It Boosts Your Metabolism

By increasing your heart rate and giving you more energy, phentermine also helps improve your metabolism. This affects how many calories you burn, which means that you'll be able to get an even bigger benefit out of your exercise plan.

How much weight can you lose with Acxion? ›

Q: How much weight loss can be achieved with Acxion pills? Ans: In a study, it is clinically approved that by taking Acxion including phentermine for 12 weeks, an average weight reduction of 3.8kg was noted.

What happens if you don't lose weight on phentermine? ›

However, if phentermine doesn't work, stops working, or has an intolerable side-effect, you should ask your physician to switch to a different weight loss medicine. There are lots of options. Some people have to take other medications which cause weight-gain; other patients have genetic obesity.

Can you build up a tolerance to phentermine? ›

In this study, we also found that almost 66% of subjects developed tolerance to phentermine (25% and 41% at months 2 and 3, respectively), defined as a BWR% lower than or equal to that achieved in the previous month.

What should you not eat when taking phentermine? ›

Foods to Limit on a Phentermine Diet
  • Junk foods: fast food and potato chips.
  • Refined carbohydrates: white bread, pasta, crackers, flour tortillas, biscuits.
  • Fried foods: french fries, donuts, fried meats.
  • Sugar-sweetened beverages: soda, tea with added sugar, sports drinks.
26 Aug 2021

Does phentermine make you poop? ›

The more common side effects of phentermine can include: bad taste in your mouth. constipation. diarrhea.

What gives you energy like phentermine? ›

Leanbean is one of the top phentermine alternatives for women. If you're struggling to find the energy to lose weight, this supplement will give you the boost you need to maintain a healthy routine.

What does it mean if phentermine makes you tired? ›

Why am I tired on Phentermine? Fatigue or tiredness can come as a result of sleepless nights or following a period of over-stimulation, however, adverse effects of phentermine also include drowsiness, fatigue, and reduced energy levels.

What vitamins should I take with phentermine? ›

Replenish Depleted Nutrients
  • Biotin. ...
  • Calcium. ...
  • L-Carnitine. ...
  • Vitamin A. ...
  • Vitamin B12. ...
  • Vitamin D. ...
  • Vitamin E.

How long does it take for phentermine to show results? ›

Phentermine starts to work very quickly after taking an initial dose. Phentermine medication gets absorbed through your gastrointestinal tract. It will reach its peak concentrations in your blood after three to 4.4 hours. You should start feeling the effects in around four hours.

What should I eat while taking phentermine? ›

Great sources of fiber are beans, whole grains and brown rice, nuts, baked potatoes (but you have to eat the skin), berries, bran cereal and vegetables. Fruits and Vegetables: The water and fiber in fruits and vegetables will add volume to your dishes, so you can eat the same amount of food with fewer calories.

Can I have caffeine with phentermine? ›

Notes for Consumers: Limit Caffeine intake (examples: coffee, teas, colas, chocolate, and some herbal supplements) while taking Phentermine. Also avoid medicines containing additional Caffeine whenever possible. Side effects from Phentermine may get worse if you take excessive Caffeine.

Does phentermine eventually stop working? ›

If you take phentermine and continue on with the same food choices that lead to your being overweight, you will lose weight short-term, because you will be eating less, but eventually the medication will stop working and you will be right back where you started.

What does phentermine do to your hormones? ›

Phentermine also works outside of the brain, triggering the release of adrenaline and epinephrine, hormones which have powerful fat-burning properties. Paired with a dietary strategy, phentermine achieves significant weight loss.

How long can you be on phentermine? ›

The Food and Drug Administration (FDA) limited treatment to 12 weeks or less.

How can I lose extreme weight fast? ›

15 Expert-Backed Tips for Safe and Sustainable Weight Loss
  1. Implement Long-Term Lifestyle and Behavior Changes. ...
  2. Focus on the First 5% to 10% ...
  3. Reduce Your Intake of Ultra-Processed Carbs and Sweets. ...
  4. Eat More Plants. ...
  5. Pump Up Your Protein. ...
  6. Drink More Water. ...
  7. Eat a Well-Rounded Breakfast. ...
  8. Stand Up and Move More.

When is the best time to take phentermine? ›

The medication is usually taken with or without food once a day in the morning. This medication may cause difficulty falling asleep or staying asleep if it is taken in the evening. Take phentermine and topiramate at around the same time every day.

What does phentermine 37.5 mg do? ›

Phentermine (Adipex-P, Lomaira) is an amphetamine-like prescription medication used to suppress appetite. It can help weight loss by decreasing your hunger or making you feel full longer.

How much water should I drink while taking phentermine? ›

The first rule of every diet is to drink lots of water. When taking phentermine you should be drinking at least 8 glasses diet water per day in order to improve the functions of your body and assist in the release of water weight, as well as keeping you hydrated and less likely to misinterpret thirst for hunger.

Does phentermine burn fat or muscle? ›

Phentermine is a prescription weight loss medication. It is an appetite suppressant. Individuals taking phentermine lose weight because they are less hungry and thus consume fewer calories. Phentermine does not cause you to burn fat and does not affect your metabolism.

Does phentermine work for everyone? ›

Phentermine is for people with obesity or those unable to lose weight with a balanced diet and exercise alone. They should have a BMI over 30 , or over 27 with a weight-related condition. Importantly, a person should still make dietary and lifestyle changes to support their weight loss for the drug to work correctly.

Is Acxion the same as phentermine? ›

As we mentioned before, Acxion's star ingredient is Phentermine (more specifically, phentermine hydrochloride), without extra additions. Some pharmacies also sell 6.4mg version. According to the directions on the Acxion package, the user should take 15-37mg every morning, one to two hours after breakfast or before it.

Can you take 2 phentermine a day? ›

The dosage may be adjusted to the patient's need. For some patients, half tablet (18.75 mg) daily may be adequate, while in some cases it may be desirable to give half tablets (18.75 mg) two times a day.

What are the side effects of Acxion? ›

Acxion diet pill's most common side effect is Dry Mouth which users might experience from time to time. Overdosing Acxion pills may result in GI problems such as diarrhea, constipation, and flatulence. Nausea is another side effect that most of the time leads to vomiting.

How long does it take to start losing weight on phentermine? ›

The bottom line is that phentermine works in just three to 4.4 hours. However, it may take a couple of weeks before you start to notice that you're losing weight. To see your results as quickly as possible, you should try to minimize your consumption of carbohydrates, stay hydrated, and stay as active as possible.

How much weight can you lose with Acxion? ›

Q: How much weight loss can be achieved with Acxion pills? Ans: In a study, it is clinically approved that by taking Acxion including phentermine for 12 weeks, an average weight reduction of 3.8kg was noted.

What happens if you don't lose weight on phentermine? ›

However, if phentermine doesn't work, stops working, or has an intolerable side-effect, you should ask your physician to switch to a different weight loss medicine. There are lots of options. Some people have to take other medications which cause weight-gain; other patients have genetic obesity.

Does phentermine speed up your metabolism? ›

It Boosts Your Metabolism

By increasing your heart rate and giving you more energy, phentermine also helps improve your metabolism. This affects how many calories you burn, which means that you'll be able to get an even bigger benefit out of your exercise plan.

Why does phentermine work so well? ›

It works by activating your sympathetic (“fight or flight”) nervous system, so it's called a “sympathomimetic” drug or “stimulant.” Phentermine may help lower your appetite, so people who take phentermine tend to eat less.

Do you have to exercise when taking phentermine? ›

We recommend that you include exercise into your routine in order to maximize your results with phentermine. Exercise is important because not only does it help with weight loss, but it can also help boost your energy, help suppress your appetite, improve your mood, and even help with menstrual cramping.

How many calories should you eat on phentermine? ›

We recommend that you accompany the phentermine with a 1500-calorie diet with 20-25 grams of fat per day. We have American Diabetes Association diets to help you plan your meals – or you may prefer to use Weight Waters or NutriSystem meals. Exercise is an important part of the diet regimen.

How much water should I drink on phentermine? ›

When taking phentermine you should be drinking at least 8 glasses of water per day in order to improve the functions of your body and assist in the release of water weight, as well as keeping you hydrated and less likely to misinterpret thirst for hunger.

Is Acxion the same as phentermine? ›

As we mentioned before, Acxion's star ingredient is Phentermine (more specifically, phentermine hydrochloride), without extra additions. Some pharmacies also sell 6.4mg version. According to the directions on the Acxion package, the user should take 15-37mg every morning, one to two hours after breakfast or before it.

Can you drink caffeine while taking phentermine? ›

Notes for Consumers: Limit Caffeine intake (examples: coffee, teas, colas, chocolate, and some herbal supplements) while taking Phentermine. Also avoid medicines containing additional Caffeine whenever possible. Side effects from Phentermine may get worse if you take excessive Caffeine.

What does it mean if phentermine doesn't work? ›

Why does phentermine wear off? The effects of phentermine are diminished over time due to drug tolerance. Tolerance is when a medication loses potency over time after repeated use and as a result the individual experiences less response from the drug.

What should you not eat when taking phentermine? ›

Foods to Limit on a Phentermine Diet
  • Junk foods: fast food and potato chips.
  • Refined carbohydrates: white bread, pasta, crackers, flour tortillas, biscuits.
  • Fried foods: french fries, donuts, fried meats.
  • Sugar-sweetened beverages: soda, tea with added sugar, sports drinks.
26 Aug 2021

Can you lose weight on phentermine alone? ›

Like other prescription weight-loss drugs, phentermine is intended to be used as part of an overall weight-loss plan. It is indicated for people who are obese, and who have failed to lose enough weight with diet and exercise alone — not for people who want to lose just a few pounds.

What gives you energy like phentermine? ›

Leanbean is one of the top phentermine alternatives for women. If you're struggling to find the energy to lose weight, this supplement will give you the boost you need to maintain a healthy routine.

Does phentermine burn fat or muscle? ›

Phentermine is a prescription weight loss medication. It is an appetite suppressant. Individuals taking phentermine lose weight because they are less hungry and thus consume fewer calories. Phentermine does not cause you to burn fat and does not affect your metabolism.

Does phentermine make you poop? ›

The more common side effects of phentermine can include: bad taste in your mouth. constipation. diarrhea.

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