Do diet pills actually work?

Diet pill concept: How lazy can we get?


The idea of losing weight fast is so appealing and generates the supplement industry countless millions of pounds every year. It plays so well into human nature. We are always looking for a quick fix.

Why change my lifestyle when I can just take these pills and melt away the fat?

However, the diet pill industry is not just a scam its a potentially fatal one. More than just a few people have died after taking diet pills filled with a re purposed herbicide known as DNP. All the victims were normal people, usually quite young, looking for a way to quickly drop a few pounds. What did they get for their cash? A gruesome end, which I cover further down the article. It’s tragic but unfortunately not that uncommon for people to literally die after taking dodging supplements and weight loss aids bought online. As I’ve said before, the supplement industry is poorly regulated and the internet is awash with scams that fall under the radar of law enforcement.

It has never been more important to be aware of what these sort of products contain and that you could be putting yourself in serious danger by buying into these ‘quick-fix’ ideas. I’ve written this article in the hope that you re-consider buying dubious items online that you intend to put into your body.

There is an important distinction to be made between ‘Diet Pills’ and ‘Anti-Obesity Pharmaceuticals’. Pharmaceutical drugs specifically designed to combat obesity often target receptors and systems involved in appetite control, fat deposition, blood glucose regualtion and energy expenditure. These drugs target important and delicate parts of your physiology and are designed and tested through a development process usually costing 10s of million of dollars. Obesity is big business after all. The compound I am working on during my PhD for example, currently falls into this category. It is a drug which mimics the actions of natural PYY in the body. PYY is released after we eat to signal us to stop eating. It is a very powerful anorectic hormone and induces the satiety response.

Diet pills on the other hand, tend to have far less or no developmental costs, are scams, are dangerous or have dubious science backing them up. Examples would be over the counter tablets or supplements bought online – Green Tea Extract, being a prime example, which I have written about extensively here. There is a big difference, of course, between diet pills that simply don’t work and pills which contain toxic chemicals, I talk about these dangerous pills a bit later on. The issue with cheap internet products is you simply never known for sure what is in the pill.


Examples of diet pill and their physiological function


Actual medications

Orlistat – A well known anti-obesity medication. Works by reducing intestinal fat absorption. The end result is that you poop out more fat. Due to the way it works, side effects are mainly restricted to gastro-intestinal disturbances, the most common being extreme flatulence and oily bowel movements. Not life threatening by any means but a fairly heavy price to pay when you could just eat less fat! Orlistat has been available over the counter for a around a decade but used to be prescription only. Does actually appear to work based no available studies with participants losing modest weight when taking the drug (x).

Is it worth the oily poop?


Liraglutide – A long acting analogue of GLP-1, primarily used in the treatment of type 2 diabetes. GLP-1 produces a number of physiological effects useful in the treatment of obesity. For example, it reduces the rate of gastric emptying and promotes a feeling of satiety – the satisfying fulfilled feeling after a big meal (1). The draw backs of form of this drug is that weight loss is not observed in all patients and nausea is a common side effect (2).


Metformin – Also primarily used in the treatment of type 2 diabetes. Metformin limits the amount of glucose produced by the liver whilst increasing muscle uptake of glucose (3). Naturally this serves diabetics well, who need to manage glucose in the blood closely. Metformin has also been shown to reduce weight in diabetic patients but is not prescribed specifically for that purpose (4).

Although a few years old, this endocrinology review details the efficacy of current anti-obesity therapies, going into detail regarding the available data.


Diet pills

Green tea extract – Currently very popular as an ‘alternative’ weight loss aid and can be found both online and in almost any health food shop you walk into. The science suggesting green tea can actually reduce your weight is dubious at best and usually comes from poorly designed studies. Take a look at this article I’ve written for an in-depth look at why green tea is an expensive waste of money. The upside of green tea pills is that they aren’t dangerous. They simply don’t work as they say they should.

Utter crap


DNP tables – I talk about this further down the article. DNP is a toxic compound mainly used in the industrial manufacture of pesticides and herbicides. It also has an ‘uncoupling’ effect on mitochondrial energy production which means instead of calories ultimately making energy for use by your cells, the calories go towards generating heat. You essentially burn through extra calories  through increased heat production. Despite what a lot of shameful, cheap websites tell you, DNP is fucking dangerous and has directly led to the deaths of numerous people. NEVER TAKE THIS.

Amphetamine-based tablets – Amphetamine based products have a legitimate use in treating ADHD and narcolespy. Aside from that they should be avoided. They are well known performance enhancers and are of course banned at sporting events and competitions. Amphetamine use is associated with weight loss due to appetite suppressant effects. However, amphetamines are addictive and mess with numerous aspects of physiology not to do with weight and appetite management. There is also evidence that long term use may interfere with normal dopamine signalling in the brain. Avoid!


So do they work?

The answer is both yes and no depending on the drug. Under the umber all of pharmaceutical anti-obesity therapies, some patients do show modest weight loss. However, these sort of drugs are rife with side effects and many have been pulled after only a few years on the market, rimonabant being one example. So in one sense they can help with weight loss, but they cannot be taken indefinitely and the risk of side effects likely outweighs the benefits of weight loss in a lot of cases.

Now if we then look at cheap over the counter or internet pills then the answer is a firm no and if they do help with weight loss then the reasons for this are usually sinister and or damaging to your health. Most diet pills that can actually lead to weight loss contain some sort of stimulant to achieve these effects. Caffeine is a well known appetite suppressant and also a physical performance enhancer. It stands to reason that a caffeine pill and a gym session might help you lose more weight in the long run. Caffeine has been well studied in regards to human fitness and health and I’ve written about it here. Caffeine is a safe stimulant. Other pills might contain derivatives of amphetamines – addictive stimulants that should always be avoided. The point remains that you simply don’t known what these pills contain so even if weight loss were possible you would be better off with a coffee before your gym session.



.Why should you avoid them?


Aside from numerous side effects associated with pharmaceutical interventions, the internet is littered with cheap and often dangerous diet pills. Every year or so a news story will crop up about someone who has died due to taking dodgy diet pills.

This story from last year  highlights the dangers of a substance found in a number of diet pills called dinitrophenol or DNP for short.

In fact a shocking number of other deaths  have been attributed to DNP. Here, here and here are just a few examples over the past two years. Unsuspecting people trying to boost their fat loss, bought innocent looking pills online and suffer a truly horrible death as a result. This is serious and those responsible for manufacturing and selling these pills should be utterly ashamed of themselves.

The common theme in these stories is that the victim is described as ‘cooking’ or ‘boiling’ from the inside. Although an over-simplification, this is a grim and horrible truth.

DNP is an organic compound most commonly used as a pesticide and antiseptic (5). It is also used to make a number of herbicides and wood preservatives. Not exactly the sort of thing you want to be eating right? Well, DNP has been used in high doses as a weight loss aid with disastrous consequences (6) In mammalian biology, DNP inhibits ATP production in mitochondria-containing cells (7). That is mental. ATP is essentially the life source of all cells, powering innumerable operations in the cell (8). Mess with ATP production and it will end in disaster. Interestingly, cyanide poison also interferes with cellular respiration and ATP production and we all known how deadly that is (9).

So why are these people who died from DNP pills described as cooking alive? It’s down to how DNP effects you on a cellular level. It acts as a protonophore, quite literally allowing protons to leak across the inner membrane of mitochondria, the site of respiration and ATP synthesis. As the protons leak where they shouldn’t they avoid interacting with a peptide called ATP synthase – a critical component in the system that makes ATP. Energy production therefore becomes much less efficient as part of the fuel to make it is leaking. In response to this inefficiency, the metabolic rate continues to accelerate to produce enough ATP to keep the body working. It does this by burning more and more fat tissue – which is very rich in calories. This is proportional to the amount of DNP taken.  In a nutshell, DNP ‘uncouples‘ ATP synthase from oxidation. Uncoupling is very important for rodents-it allows them to generate heat instead of ATP when they are very cold. Humans rely far less on this. Uncoupling leads to heat generation. Large doses of DNP lead to massive uncoupling and therefore large amounts of heat are generated (10).

Due to this, DNP causes fatal hyperthermia. Adding another terrible aspects to this is that the process isn’t instant. Instead, the body temperature rises gradually followed by coma and death. In  a sense your truly do ‘cook to death’. In a few harrowing stories, victims are told nothing can be done for them once they have been admitted to hospital. The drug is in the system, the ATP process is disrupted and a massive body temperature increase is unavoidable.

Is it worth taking ‘diet pills’ bought online? A FIRM NO. At best, they fail to work, at worst they can be fatal. You simply cannot tell for sure what is in them.

What about specifically developed pharmaceutical drugs? Consult with your doctor but unless you are being treated for Type 2 Diabetes Mellitus with a drug that also leads to weight loss, I would avoid any anti-obesity medications as they currently stand.

My stance on this will likely change in the future. We still have a largely incomplete understanding of how the brain and body ultimately control appetite and energy regulation. We know the basics and that’s a great start but until we uncover more we can’t develop truly effective anti-obesity medications with limited side effects. We are messing with a system that is absolutely fundamental to out survival – we must be careful.




There aren’t any quick fix alternatives! Like most things worth doing, there isn’t usually an easy or quick route. When it comes to your health, a quick fix is not what you should aim for – it’s like duct taping a damaged tire, it’s not getting to the route of the problem and it will get worse over time.


Moderation, diet and exercise – that’s the key to a healthy body. Some may find it much harder than others but it is possible for the vast majority of people.


The health food and supplement industry cleverly relies on standard human behaviour. Take this pill for X, this pill will grow your penis a metre, this will make you lose 10 kgs. It’s like if someone offers you an investment opportunity with 80% returns in a month – its almost always too good to be true and this is no different.

Losing weight (that stays lost!) requires a change to your lifestyle in general, including your eating habits, your sleep schedule and the amount of exercise you do. These pills sell in there thousands because the manufacturers known how daunting a ‘lifestyle change’ sounds.

If you are serious about getting in better shape don’t forget to check out these other useful articles including top exercises for muscle building at the gym or at home as well as reading up on popular supplement scams and why you shouldn’t waste your money!


Whey protein guide: A complete guide to popular whey protein supplements

Creatine guide: Learn all the science behind this popular powder and how it can help towards your fitness goals

TOP 5: Mass building exercises


Before you buy these popular supplements – have a look at the real science behind their use, it may surprise you:

Multivitamin Hoax

Green Tea Facade


Finally, don’t forget to check out the supplement shop that only recommends products that have been tested in well designed studies and which have worked for me personally.


Thanks for reading,


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