Phentermine Alternatives

Phentermine is a well known weight loss aid that dates back decades but as it’s not available over the counter many people look for Phentermine alternatives. In this guide, we assess the best options.

phentermine alternative header

Plenty of people have a fitness goal or two on the go at any one time. These may be performance based, skills based, or, commonly, rooted in body composition. It’s common to want to lose body fat, either as part of a larger weight loss drive or as a cutting phase during a more cyclical routine.

There are plenty of supplements that can help.

Few drugs or their natural alternatives can lead to weight loss in themselves. You will only ever be able to lose weight by putting a calorie deficit into place. Consume 500 calories fewer than your body needs each day to lose roughly 1 lb (0.5 kg) per week.

You can do this simply through your diet – literally undereat by 500 calories per day. Or you can do this through your exercise regime – try to burn off an extra 500 calories per day by being more active (no small thing to achieve.) Realistically, the best approach is to go with a hybrid of these two – eat 300 calories fewer per day whilst burning an extra 200 calories through exercise, for example.

However, certain supplements can give you an edge, here. They can help keep your metabolism boosted or optimized, whilst giving you extra energy and keeping hunger pangs at bay.

Phentermine is a classic weight loss medication dating from the fifties. It is a prescription drug designed to bring about rapid weight loss. However, it is well regulated. You can only get it on prescription (though this doesn’t stop certain bodybuilders and their ilk from getting their hands on it.)

However, there are some great phentermine alternatives out there. These are all-natural compounds designed to aid in weight loss, keeping your body in a perfect state to make the most out of your calorie deficit and training program.

We’ve recently looked at a few and will be shortlisting them below for you to choose the most suitable option for you.

phenq bottle

PhenQ – Top Phentermine Alternative

PhenQ is consistently one of our top performers in the weight loss and fat burning categories. It is a safe and effective alternative to Phentermine and we endorse it as our top pick.

What is Phentermine?

As above, phentermine is a prescription drug, well-regulated and controlled. You can only get it through your medical provider. A doctor will generally only prescribe it where drastic weight loss is needed – where the cost of staying at your current weight is greater than the costs inflicted by taking phentermine and rapidly dropping body fat. In short, you will only be given it if you are dangerously, life-threateningly obese.

Phentermine serves two functions.

Firstly, it will keep your appetite low, leading you to eat less. This can be particularly useful for people with portion control or uncontrollable hunger pangs. Secondly, it boosts your metabolic rate, so that your body will burn through fat a lot faster.

There are, however, several quite severe side effects that make phentermine use only appropriate in equally severe cases. It can cause heart palpitations, nausea, and high blood pressure. There are psychological effects associated with it, making it hard on those with mental health concerns (which often go hand-in-hand with obesity). In some cases, use has been lined with heart and lung disease.

Phentermine can also be highly addictive.

There are no legal, safe, perfect alternatives to Phentermine. You shouldn’t try to find one.

What we are looking for are natural products with no side effects that manage to hit the same two primary functions as phentermine – we want products that can curb hunger whilst keeping your metabolism functioning optimally.

Our Top Phentermine Alternatives


PhenQ bottles

PhenQ is one of the best natural weight loss aids on today’s market. It is perfect for boosting your metabolic rate to its natural potential whilst keeping you feeling fuller and more energized for longer. 

It’s made by Wolfson Berg, one of the world’s leading supplement companies, so you can rest assured that it has the pedigree you would want for your money.

PhenQ focusses mostly on increasing thermogenesis (basically, boosting your metabolism). Thermogenesis is a completely natural process that our bodies do all the time to keep us alive. In essence, it is the process of converting fat to energy, raising the body’s temperature as it does so.

Thermogenic fat burners – which refers to pretty much all decent phentermine alternatives – will use a range of ingredients to influence and raise the body’s metabolic rate. The end result is more fat burned and more calories used.

We can find a few powerful, natural ingredients in PhenQ – the kinds of ingredients one would expect of a leading weight loss supplement like this. These include a trademarked formulation called A-Lacy’s Reset, which is made to boost thermogenesis. You also get chromium picolinate, which is a trace element that plays a prominent role in storing and using nutrients.

Then there is nopal, l-carnitine tartrate, capsicum extract, and calcium carbonate. Once more, these are all standard ingredients for this kind of supplement. They will promote healthy metabolic function and a feeling of lasting fullness.

Finally, you get a decent amount of caffeine anhydrous, for added energy as well as improved rates of thermogenesis.

PhenQ should do exactly what you want from a phentermine alternative – it should reduce your appetite whilst improving your metabolic function. There are no side effects associated with it – all ingredients are completely natural and it makes it comfortably in as our number one choice.

  • The results are great, from improved strength to heightened mood and energy
  • Natural, safe ingredients
  • Mimics phentermine very ably, raising metabolism and decreasing appetite
  • Few reported side effects, none of which are severe
  • Very good scientific backing
  • Improves long and short term energy levels
  • A high caffeine content isn’t appropriate for everyone


prime shred fat burner

Next up we have a supplement branded to appeal to gym rats and body builder types: PrimeShred. 

It is a potent formula designed to help users maintain lean, athletic physiques. It is perfect for those looking to train hard and maintain high muscle mass as they cut down on their body fat levels. However, though it is primarily marketed in this way, there is nothing about PrimeShred that sets it apart too much – it will be good for anybody looking to lose weight, no matter their athletic aims or training style.

As with everything on this list, all the ingredients used in PrimeShred are completely natural.

It uses the same kind of formula as PhenQ to mimic the effects of Phentermine without any of the nasty side effects or associated health concerns.

The formula includes fantastic, high-potency, high dosage ingredients all guaranteed to help you on your weight loss journey. This includes ingredients like green tea, green coffee, and caffeine anhydrous for added energy and thermogenesis, alongside cayenne pepper, B vitamins, DMAE, l-theanine and l-tyrosine, and bioperene.

With all of these combined together, you should see similar results to phentermine – improved metabolic function, heightened energy levels, and reduced hunger pangs and cravings.

  • Diverse and effective ingredients profile
  • Everything is well dosed
  • Natural and largely free from side effects
  • Suitable for plant-based diets
  • Very appropriate for athletic lifestyles, and for use as a pre-workout supplement
  • On the pricey side of things
  • Can cause upset stomach and digestion at first
  • A high caffeine content isn’t appropriate for everyone


leanbean packaging

Supplements are increasingly becoming more and more suitable to plant-based diets, foregoing animal gelatine capsules and the like to allow access for vegetarians and vegans. Whilst it’s not the only vegan-friendly product on this list, Leanbean is something of a frontrunner in the fight to bring plant-based lifestyles and the world of fitness together.

It is a phentermine alternative for anyone looking to follow plant-based diets with purely natural ingredients. It isn’t only for those on plant-based diets, though – anybody looking to lose weight would benefit from this powerful formula.

There is a thermogenic element to Leanbean, so it will raise your metabolism to an optimal amount for weight loss. It achieves this through the inclusion of choline and chromium, which will boost your metabolism whilst regulating blood sugar levels. However, most of the magic comes from the inclusion of glucomannan in the recipe. Glucomannan is often found in weight loss supplements – it’s a natural fiber that is perfect for improving feelings of satiation and normalizing digestive health (which can often suffer during a calorie deficit.)

It is quite low on stimulants. This robs it of a little efficacy, as caffeine and the like have a thermogenic effect and lead to higher energy levels. However, stimulants like this are far from perfect for everyone. In fact, too much caffeine in your diet can be outright dangerous. Leanbean is therefore perfect for anyone looking for a weight loss aid without wanting to chug stimulants.

  • Includes glucomannan, one of the best fiber sources going
  • Should suppress appetite and improve digestive health
  • All natural ingredients, fully vegan friendly
  • Should stabilize blood sugar levels
  • You need to take three servings per day, which can be a bit of a hassle
  • Low on stimulants, which may be unsuitable for some

Instant Knockout 

instant knockout bottle

Instant Knockout was originally developed for MMA fighters and professional boxers. The idea was that it would allow them to slim down ahead of weigh ins whilst enabling them to maintain the muscle mass for which they had (literally) fought. They would be able to shed the pounds they needed without losing much by way of athleticism, strength, or power output.

However, much like PrimeShred, this is all just hype and branding, in the end. If you’re a fighter looking to lean down without losing any athleticism, you will do well on Instant Knockout. However, if you’re just an everyday Joe public type looking to lose a little weight, keeping everything optimal as you do, it will be perfect for you, too.

Instant Knockout will keep you on your toes (pun intended). It will mimic phentermine in reducing appetite and boosting metabolic rates. It also includes plenty of stimulant action – this is mostly from a full 350 milligrams of caffeine. This should give you improved energy levels and mental clarity, making it much easier to maintain an active lifestyle.

It also uses green tea extract, black pepper extract, cayenne pepper, and vitamins D and B. These will all work together to improve insulin sensitivity, keeping hunger pangs and energy crashes to a minimum, whilst improving rates of thermogenesis.

Everything is vegan friendly; everything is natural: what’s not to like?

  • Plenty of energy with lots of caffeine and green tea
  • Works well in an athletic situation
  • Great for pre-workout supplementation
  • Suitable for plant-based diets
  • All natural ingredients
  • Will boost metabolism and lead to lasting feelings of fullness
  • Bordering on an unhealthy level of caffeine with each dose


phengold 3 bottles

PhenGold, from the very well-known, very well-respected Swiss Research Labs Ltd, makes up the final offering on our list today. It’s one of the best phentermine alternatives going, from one of the best supplements companies in the world.

As with everything else on this list, PhenGold uses entirely natural ingredients, keeping side effects to a minimum, and ensuring that any side effects that do arise are short lived and very moderate. Everything is suitable for vegetarians and vegans.

Swiss Research Labs Ltd have gone all in on metabolic boosting with PhenGold. It will promote increased fat burn and energy use through greatly improved rates of thermogenesis, keeping your energy levels very high.

This high energy is aided in large part by plenty of caffeine in the formula (225 milligrams, which is a lot!) combined with green tea extract. These, alongside cayenne pepper, should keep your metabolism functioning at its fullest.

The really clever part about PhenGold comes with its cognitive benefits, however. Calorie deficits are renowned for keeping you a little foggy headed, clouding your cognitive awareness, making you feel lethargic, and generally sapping your ability to think clearly. PhenGold includes 150 mg of dimethylaminoethanol, one of the best commercially available nootropics going.

Dimethylaminoethanol should help to improve your brain function, giving you more mental awareness and energy, and plenty of clarity.

  • Mental clarity should be improved
  • Great for boosting energy levels, both short and longer term
  • Boosts thermogenesis, mimicking this element of phentermine well
  • Plenty of multibuy offers available on their website
  • Not much by way of appetite suppression, lacking a little of phentermine’s potency in this regard
  • High caffeine intake isn’t suitable for all users

Do Phentermine Alternatives Work?

Yes, they can work very well. As we have seen in the products on our list, natural ingredients can help to suppress the appetite, optimize metabolic function, and increase energy levels. This is everything that phentermine promises, without the side effects and health complications.

Nothing on this list will be as potent as phentermine, though. You won’t shed weight as quickly or as effortlessly using these as you would if you were on phentermine. However, if you cannot get a prescription for phentermine, the chances are you don’t need to lose weight so quickly or effortlessly.

You can get these alternatives online, readily available, without any of the health risks. That more than makes up for a dip in potency.

How To Choose Good Phentermine Alternatives

If you’re looking for a phentermine alternative, you are looking for something that can reduce hunger cravings, give you more energy, and optimize metabolic function to aid in weight loss. Anything from the list above will serve you well in all of these regards. Pick a suitable looking candidate from them and you’ll be onto a winner.

Also, adjust your expectations. As above, no natural alternatives will be as potent as phentermine. They aren’t trying to be – this is the point. They are safe, natural, readily available dietary supplements, not harsh drugs that will achieve your goals at the expense of your health. Don’t look for anything promising miracles. If they can deliver, they likely aren’t safe; if they are safe, they likely can’t deliver.

Simply expect to get what these alternatives offer – optimization to a natural limit, hunger suppression, and a little extra energy.

To get these things, you will need to source alternatives with strong ingredient profiles – made up of the kinds of ingredients we have seen scattered throughout our list, in reasonable doses and quantities. 

Ingredients like caffeine, vitamin B6, green tea and green coffee extracts, l-carnitine, capsaicin, cayenne pepper, and glucomannan should feature prominently.

Make sure there is something of worth in the ingredients list. Make sure, too, that the ingredients are all clearly listed with their doses. If a supplement hides ingredients or doesn’t tell you how much of any given ingredient is included, don’t buy it. You need to know what you’re putting into your body; you need to know that it won’t damage you and that anything usable is included in high enough doses to actually make a difference.

What To Avoid When Buying A Phentermine Alternative

As above, avoid anything that hides ingredients or doesn’t tell you how much of any given ingredient is included. Avoid anything that doesn’t include any of the main ingredients we’ve mentioned today. A supplement like this could be a useless waste of money at best. At worst, it could be outright dangerous.

There are also some common ingredients that you should stay well away from. They are often included in riskier formulas, with plenty of good results mixed in and made murky with unhealthy side effects. These include:

  • Dinitrophenol (DNP), a heavy hitting metabolism booster that can be fatal. It is also highly illegal, so if you come across a product claiming to contain it, report it to the relevant authorities. Do not be tempted to buy.
  • Ephedra, which increases your blood pressure and heart rate as well as helping you to lose weight. Increases to both will put you at risk of chronic conditions such as heart disease and stroke.
  • M-synephrine, which also increases blood pressure and heart rate, though less noticeably than ephedra. It can be safe enough by itself but can be very dangerous when combined with stimulants such as caffeine. It can also cross the blood-brain barrier, so you really don’t want to be putting it in your body. It’s also often sold as p-synephrine or o-synephrine, so watch out for these, too.


Can online doctors prescribe phentermine?

The DEA does not allow online doctors to prescribe phentermine. At the moment, it can only be prescribed through a face-to-face, in person consultation. Furthermore, it usually won’t be the first treatment offered – it is something of a last resort, with lifestyle and dietary changes coming first.

What fat burners do bodybuilders use?

Natural bodybuilders will tend to pair products like those in our list – good quality phentermine alternatives – with healthy diet and lifestyle choices. Non-natural bodybuilders, which is likely a majority of them, will tend to use more dangerous substances. These can include the steroid clenbuterol and, of course, illicit phentermine.

Are fat burners worth it?

Fat burners can be very worthwhile. Natural compounds like those in our list will never lead to weight loss by themselves. However, they are fantastic supports for calorie deficits, keeping your metabolic rate optimized, giving you plenty of energy, and minimizing hunger pangs and cravings.


The products we have looked at are all great natural phentermine alternatives. Any one of them will represent a worthwhile dietary aid as you open up a calorie deficit and lose body fat. They will all keep you as metabolically active as possible whilst giving you the energy you need to live a full and active lifestyle.

However, there is always a clear winner. For us, it’s the one with the most proven results, with the best scientific backing, and with the best, most well-rounded formula. This is PhenQ, one of the best supplements on the modern market, and one of the best phentermine alternatives going.

phenq bottle

PhenQ – Top Phentermine Alternative

PhenQ is consistently one of our top performers in the weight loss and fat burning categories. It is a safe and effective alternative to Phentermine and we endorse it as our top pick.

Written by Kate Harrison

Kate is one of our nutrition experts at PathMed and is also one of our in-house writers. There is little that gets past Kate when it comes to nutrition and she has a wealth of experience when it comes to fat loss and supplementation around losing weight. She is thorough in her research and is a real advocate for living a healthy lifestyle.