Combining Phentermine with Other Supplements

Combining Phentermine with Other Supplements

Are you on phentermine and considering using other supplements too? Are you already using other supplements yourself? The products that are commonly brought up by phentermine users are pre-workout supplements, melatonin, vitamin B12, capsicum, and CLA. Today we’ll be looking at the popularity of these supplements and if they are safe to use with phentermine.

Please note, always talk to your prescribing doctor and pharmacist and get their opinion before you combine medications and supplements with phentermine. Medical professionals are in the best position to assess the potential for interactions or negative side effects. They can consider your individual medical condition as well as the other OTC and prescription drugs you are on to make an informed suggestion.

Melatonin and Phentermine

Melatonin is a great sleep aid, which is why many phentermine users will seek it out, particularly those who have problems with insomnia when taking phentermine. However, be sure to talk to your doctor before taking melatonin with phentermine given the opposite effects of the two substances.

What is Melatonin?

Melatonin Melatonin supplement is a hormone the body uses to control the sleep-wake cycle. It is made naturally in the pineal gland of the brain, but it can also be taken in the form of a dietary supplement. These melatonin supplements are available as pills, sub-lingual tabs, and gummies. The average dose is between 1 and 10 milligrams.

These supplements are primarily used to treat sleep disorders and adjust sleep schedules. They are used to deal with jet lag, insomnia, shift changes, and other sleeping issues.

Researchers are still considering and assessing other potential uses of the hormone. While it can work great for some users, others have noted that there is little difference when they take melatonin.

While melatonin is better-tolerated than other sleeping aides in general, it can’t be considered completely harmless. It can trigger headaches, dizziness, stomach aches, daytime sleepiness, and mood changes including anxiety and depression.

Melatonin can also cause issues if taken alongside other medications including immunosuppressants, blood thinners, birth control pills, and diabetes medication.

Can I Use Melatonin with Phentermine?

Researchers have yet to fully define how melatonin interacts with phentermine. Some sources warn against the combination as phentermine increases alertness and melatonin decreases it.

It is not advisable to combine the two without first consulting a medical professional. However, melatonin has been prescribed to phentermine patients that have problems with insomnia.

If you wish to take phentermine and melatonin together, then don’t hesitate to talk to your doctor and/or pharmacist about it and get their opinion.


Be sure to talk to your doctor and pharmacist before you combine phentermine with melatonin. Some people report negative interactions, and some don’t. So it’s worth discussing the combination with your doctor or another medical professional before taking it.

Melatonin Alternatives

If you are having problems with insomnia when taking phentermine, but don’t want to take melatonin (or have been told you can’t) then here are some tricks to help you sleep easier;

  • Take phentermine early in the day. Phentermine has stimulating effects that keep you up if you take them too late.
  • Don’t have any caffeine. You should never mix caffeine and phentermine anyway – as they are stimulants – but you should be particularly careful of your afternoon tea or coffee if you are having problems with sleeping.
  • Break a sweat. Research has shown that getting regular exercise during the day makes it easier to sleep at night. Talk to your doctor and put together a great phentermine exercise regimen.
  • Turn off electronics an hour before bedtime. Read a book, listen to music, do some light stretching/yoga, or take a warm shower to relax.
  • Write it down. Are you kept up at night with worries, what-ifs, and to-do lists swimming around in your head? Take a few minutes to put it all down on paper and relax.

Phentermine and Pre-Workout Supplements

Everyone understands the importance of exercising when it comes to losing weight with phentermine. It would make sense that some people wonder if they can combine their phentermine with a pre-workout supplement to take their gym sessions to the next level.

What are Pre-Workout Supplements?

Pre-Workout Supplement Pre-workout supplements, also known as just “pre-workout” are powders taken by fitness enthusiasts before exercising to boost performance. Different brands of supplement contain different ingredients, but the most common ingredients are amino acids, B vitamins, and quick-digesting carbs. They may also contain caffeine and specialized ingredients such as beet juice.

Pre-workouts claim to boost performance through increasing energy levels, boosting metabolism, and triggering a “fight or flight” response. However, experts warn that these products generally don’t live up to their lofty claims.

Can I Take Phentermine with a Pre-Workout?

It’s recommended that you avoid taking pre-workout supplements with phentermine. As phentermine already increases energy by triggering a biological response similar to the “fight or flight” response, using a pre-workout supplement on top is basically more of the same, and this is one of those times you can have too much of a good thing.

The combination can cause negative side effects such as blood pressure and heart rate spikes. Given that you can’t be sure how your body is going to react, and as every pre-workout is different, combining phentermine with pre-workouts is generally considered a bad idea. This logic is why a healthcare provider requests you avoid caffeine as much as possible while using phentermine.


Avoid taking pre-workouts when on phentermine. If you think you could do with a boost of energy when at the gym, take a look at the alternative tips below or talk to your doctor about adjusting your phentermine schedule around your workout schedule. Some people actually use phentermine itself as a pre-workout, taking it before doing their workout and making the most of the extra energy.

Alternatives to Pre-Workout Supplements

If you have trouble mustering the energy to work out then here are some ideas to set yourself up for success in the gym without having to use a pre-workout;

  • Schedule your workouts and aim to do them when you have the most energy from phentermine. Most people feel that great rush within the first few hours of taking phentermine, so consider getting your exercises done in the morning.
  • Get some workout fuel. Have you ever get started with your exercises only to realize that it’s been hours since you last ate something and now you’ve got no energy left? If you hit a wall when working out, be sure to stay properly hydrated and nourished before even starting. When taking phentermine, it’s even more important to stay hydrated and get regular meals to avoid the unwanted side effects.

Phentermine and Vitamin B12 Supplements

Vitamin B12 Supplement Vitamin B12 is a water-soluble vitamin that is present in most animal products, such as meat, fish, dairy, and eggs. It is vital for the amino acid conversion necessary to synthesize protein, lipids, DNA, and RNA. It also helps to support the proper neurological formation and the production of hemoglobin.

While it is rare for healthy American adults to have a B12 deficiency, it is becoming more common among older adults, those with gastrointestinal problems, and vegans.

A number of weight loss clinics provide vitamin B12 supplements to support healthy weight loss. These supplements are commonly offered as injections and oral supplements and they boost metabolism and energy levels.

Despite the common use of vitamin B12, one expert has noted that supplementing vitamin B12 isn’t very effective for weight loss unless you already have a B12 deficiency. Even so, many doctors will prescribe it to combat potential deficiencies.

If you are interested in getting a vitamin B12 boot to support healthy weight loss with phentermine, discuss it with your doctor.

Can I Take Vitamin B12 with Phentermine?

Yes, you can. In fact, many people take phentermine with B12 supplements, but they always do so under the supervision of their doctor. While vitamin B12 isn’t likely to cause any toxicity, it can interact with medication.

Always talk to your doctor about any and all supplements and medications you are taking to best minimize the potential for a negative interaction.

If you are using medication for your acidy stomach or are taking metformin to manage your diabetes, you should discuss how these can interact with B12 with your doctor.


Phentermine and vitamin B12 are generally considered safe to be used together, but you should always consult your doctor first.

B12 supplements may interact with other medications, and you should never take new medications and supplements when taking phentermine without checking with your doctor and pharmacist first.

Vitamin B12 Alternatives

If you’d rather get your energy from food instead of a supplement, then check out our tips below to naturally boost energy and metabolism.

  • Get enough sleep. Sleeping has been shown to leave you eating less, better able to resist cravings and maintain peak energy levels. These effects also help to lose weight.
  • Eat regularly. Research has shown that your metabolism works at its best when you get enough calories. Avoid skipping meals and try to put away 1,200 calories a day (or 1,500 calories per day for men) to stay strong.
  • Hit the gym. Building lean muscle mass and getting into shape helps to burn more calories when at rest. People who regularly exercise also have higher energy levels on average compared to sedentary people.

Phentermine and CLA Supplements

CLA Supplement After taking phentermine for a few months, some people look for ways to boost their results – whether it’s their weight loss, in the gym, or something else. That’s when they turn to CLA supplements.

While there are no listed interactions between CLA and phentermine, the golden rule always applies; be sure to talk to your doctor and pharmacist before combining phentermine with supplements or other medications.

What are CLA Supplements?

CLA – short for conjugated linoleic acid – supplements help to reduce weight and body fat when combined with physical activity. The scientific research isn’t conclusive when it comes to the effectiveness of CLA, but many people swear by CLA and its ability to help eliminate body fat.

Studies are also inconclusive when it comes to the potential negative side effects of long-term use of CLA, particularly whether it worsens glucose metabolism and lipid profiles. This is why it is important to do some research of your own and assess whether or not CLA would be beneficial to you.

Can I Take CLA with Phentermine?

You can combine CLA and phentermine, but you should always consult your doctor and pharmacist first. The supplement can help you to lose fat and weight when taking phentermine. Some users say that it is particularly effective at increasing inches lost when combined with physical activity. Still, it is vital that your doctor is aware of any and all supplements and medications you are taking. Consult them before taking CLA.


Most people are able to combine phentermine and CLA without any problems and enjoy the fat-burning benefits of CLA, but you must always ask your doctor and pharmacist about CLA before taking it.

They are in the best position to advise you if CLA is a good fit for your specific case or not.

If you feel that CLA might benefit your weight loss, and your medical team agrees, then we recommend Bauer Nutrition CLA 1000mg. It’s one of the best supplements on the market, with CLA derived from safflower oil at a minimum concentration of 80%; the accepted industry standard.

CLA Supplement Alternatives

Here are some tips on how to naturally lose weight and slim down without CLA;

  • Eat fat-burning foods as part of your diet. Try adding some turmeric, ginger, cayenne pepper, cinnamon, and other weight loss foods to your diet
  • Build muscle. It has been shown that lean muscle burns more calories at rest than fat does. Try to build some more lean muscle and eliminate body fat to boost weight loss.
  • Work your core and tighten the muscles under your tummy

Phentermine and Capsicum (Cayenne Pepper) Supplements

Capsicum supplement Food-based supplements are becoming more popular. One of the most popular food supplements, and indeed one of the most researched, is capsicum.

Capsicum is a chemical derived from chili peppers and it has been shown to boost metabolism and help promote weight loss.

What is Capsicum Used For?

Capsicum is used to suppress appetite, boost metabolism, and curb cravings. Research has shown that adding even a small amount of capsicum to your food can help you to eat a lot less. The effects are stronger in those who don’t eat spicy food regularly.

The substance also boosts metabolism, which gets you burning even more calories – even when resting! Have you ever felt the rush of heat that comes with eating spicy food? Capsicum, much like any other spicy food, will naturally increase core body temperature.

Given that the body prefers to be at a fairly consistent temperature, the metabolism fires up to restore normal body temperature. This natural response allows capsicum to naturally boost your metabolism and encourage weight loss.

One scientific study showed that subjects used up more energy when resting for 4.5 hours after taking a capsicum supplement or eating some cayenne pepper.

Can I Take Capsicum with Phentermine?

Capsicum is a popular ingredient for curries and chili and is used for seasoning. There are no listed drug interactions between capsicum and phentermine, but that doesn’t mean that they won’t interact.

If you are considering taking capsicum supplements, be sure to talk to your doctor and pharmacist before you do.


Talk to your doctor about taking capsicum supplements on phentermine. It’s generally advised that you begin with a low dosage – such as how much you would add to your food – and then gradually increase the dose if you are able to tolerate it.

Capsicum can interact with other medications and supplements, so you should always discuss it with your doctor before using it.

Capsicum Alternatives

If you want to enjoy the natural fat-burning benefits of capsicum but don’t want to take it as a supplement, then add some spicy food to your diet. Research shows that people who eat spicy food instead of taking capsicum supplements can benefit just as much – if not more – than those who take it as a supplement. Add a little spice to your food to control cravings, reduce appetite, and boost metabolism to lose weight.

Last updated: Oct 6, 2022. Bookmark the permalink.

One thought on “Combining Phentermine with Other Supplements

Leave a Reply

Your email address will not be published. Required fields are marked *

Pin It on Pinterest