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iQOS Update – What’s Inside A Heet

IQOS Update HEETSReading Time: 5 minutes

One of the most popular pages on this site is our review of Philip Morris’s innovative iQOS heated tobacco device. That’s not much of a surprise, because iQOS has probably had more publicity than any other Heat not Burn product and it’s also the most widely available. It’s steadily rolling out beyond the first test markets and can now be bought in the UK, Spain, the Netherlands and several other countries; before too long it will be available globally as an alternative to cigarettes, and I think it’s going to be a huge success.


When Heat not Burn UK first tested the iQOS the only sticks that came with it were mild menthols. Those were not as satisfying as they could have been, but did prove the concept. Happily, during our visit to PMI’s research centre at Neuchatel a couple of months ago there was no shortage of them in all flavours, and I got the chance to try an iQOS with a full-strength tobacco stick. I’m happy to report that it was very close to the experience of smoking a Marlboro, and an excellent substitute in every way.

Sticky Stuff

Obviously, what made the difference between “Meh, this is okay” on the first iQOS test and “Wow!” on the second one was the sticks it was being fed with. That means it’s probably time to look at the sticks themselves in a bit more detail.

The baby cigarettes that go in the end of an iQOS heated tobacco device were originally called Marlboro HeatSticks, but they’ve now been rebranded as “HEETS”. Currently HEETS come in three flavours – Amber, which roughly equates to full-strength Marlboro Red; Yellow, a lighter Marlboro Gold; and Turquoise, the mild menthol version. As far as I can tell these all have the same nicotine content, and the only difference is in the flavour.

Anyway, I just called them baby cigarettes. They’re not. Yes, they look like baby cigarettes, and they come in a tiny pack of twenty, but you can’t stick them in your mouth and fire them up with your trusty Zippo. That just won’t work. Even if it did work it would be pretty pointless, because the whole idea is that you don’t burn the tobacco.

In fact there really isn’t a lot of tobacco in there to burn, anyway. Looking at a HEET, you can see that the filter seems to take up about three-quarters of its length:

HEET cut open showing inside
There are quite a few bits in here.

Not Just Tobacco

It’s not quite this simple, but we’ll come back to that. What’s in the other quarter is the stuff that gets heated, and I’ve actually had the chance to watch it being made in the factory at Neuchatel. PMI made me promise not to put all their trade secrets on the internet, but I can tell you the basics. What they do is blend selected tobaccos to get the flavour they want, then grind them to a fine powder. This is then mixed with water and some other ingredients – vegetable glycerine to keep it moist and generate the vapour; natural cellulose fibres to bind it; and guar (a natural gum) to hold the whole lot together.

This liquid mixture is sprayed onto a conveyor belt, run through a dryer then peeled off in thin sheets. The brown stuff in the end of a Heet is those sheets, rolled up like tobacco leaves in a cigar. When you load a HEET into your iQOS a steel blade in the device cuts into the roll, and when the blade heats up it creates the vapour for you to inhale. That vapour is mostly VG, loaded with aromatic flavours from the tobacco – which is why iQOS can replicate the flavour of a cigarette in a way that e-cigs can never quite manage.

So what else is in a HEET? Well, it’s not just the filter. In fact the filter itself is very short, as you can see:

Showing the separate contents of the HEET
From left to right: The tobacco, hollow tube, PLA and filter.

The actual filter is even smaller than the plug of tobacco at the other end, and it’s really only there to give you the familiar feel of a cigarette filter. Because iQOS doesn’t produce all the harsh combustion compounds you get from a cigarette there’s no real need for much filtration, so it can be very short. In fact if it was much longer it would probably soak up a lot of the VG vapour that you want to inhale.

After the filter is a loose roll of PLA, a very stable, food-safe plastic material. This is what does the real work; it slows the vapour down without absorbing it, giving it time to cool to a more pleasant temperature before you inhale it. This takes up almost half the length of the entire Heet.

Between the PLA and the tobacco is a short length of hollow tube, made of a similar material to the filter. As far as I understand it this is mainly to keep the blade away from the PLA and give the vapour a clear path to start its journey through the HEET. Then finally, at the end, you’ll find that little plug of tobacco.


Small But Complicated

So a HEET might look like a cigarette, but inside it’s a bit more complicated. This, and the fact they’re so small, means they’re also trickier to make; PMI had to do some creative rebuilding of some old but reliable cigarette-making machines to come up with something that would make HEETS.

All this effort has paid off, though. It might be tiny, but a HEET will give as many puffs as a full-size cigarette. If you get the strength that suits you those puffs are just as satisfying, too. I had a few lingering doubts about iQOS after my first experiment with it in Poland last year, but using an identical device with Amber HEETS was a totally different experience.

What’s most exciting is that, while iQOS isn’t the first generation of this heated tobacco technology, it’s still at a relatively early stage; there’s a lot of potential for development in there. I’m increasingly sure that HnB products like this have a very bright future in front of them.

If you are thinking of making the switch then please visit our online store today. We sell everything you need to get you started and at a fantastic price too, come and try the future today!

If you are an IQOS user already we are have an amazing ten different HEETS flavours to choose from, click the banner below to see them all.


20 thoughts on “iQOS Update – What’s Inside A Heet

  1. […] about was Glo, BAT’s heated tobacco product. Glo uses “Neostiks”, similar to the Heets that feed PMI’s iQOS, and as you probably know there really isn’t a lot of tobacco in these. […]

  2. Thank you so much for all these useful information you share with us. I beleive that this technology is still at its beginning and has much room for improvement. I use IQOS and amber heets for 5 months and I have to say that I am very satisfied. I hope that PMI will produce more tobacco flavours in the near future.

  3. Actually I bought both to compare. I smoke menthol which I use for both. I just wanted to know which o e was better. Granted a lot of money and I even couldn’t use the discount system in Korea.

    They both have their advantages and disadvantages. Glo looks a bit bulky and the cigarettes are a bit too strong for my taste but it always works. Iqos looks more sophisticated The cigarettes taste more like normal cigarettes but in the first package I bought there were several cigarettes rolled too tight so I couldn’t insert them into the device.

    Both glo and iqos are packed nicely over the counter.

    Which has my preference? I don’t know yet

  4. I found the Heets are packed quite tight and much more effort to get a decent pull compared to normal cigarettes.
    I found by rolling the Heet between thumb and forefinger loosened it up and I got a much better pull off it, much more like a real cigarette.

  5. I was wondering, can you maybe use HEETS on IQOS for a more than one time? Or is it pointless as there would be no smell?

    1. Hi Gabriel,

      The tobacco will have been “spent” if you follow what I mean, so trying to use it again wouldn’t work because all of the PG (that creates the wisp of vapour) would have been used up, and also the tobacco inside would be too dry to give you any flavour of note.

  6. I have been using my IQOS 2.4 now for 3 months with the menthol HEET sticks and have not had a normal cigarette since. I am very pleased with how long the charge lasts and like the flavour and sensation that it gives. I’ve recommended this to others who have now made the change. May well update to the new 2.4Plus at some point but at the moment am perfectly happy with mine.

    1. Many thanks for taking the time to reply and leave some nice feedback Susie. 🙂

      Also many thanks for recommending the iQOS to your friends too. In general we are getting some very good feedback for the iQOS, there are other heat not burn devices out there at the moment (we have tested at least eight of them) and in our own opinion the iQOS is still the best one out there. And we’re not just saying that because we sell them! It is genuinely a very well put together device that works very well.

      Anyway thanks again Susie and enjoy!


  7. Been using iqos and amber heets for 3 months now and not had one cigarette in that time and that’s after a 29 year addiction. I feel healthier in general and my oral health is much better. Sometimes the aerosol can be a bit too hot and irritating to my stomach but down the line I reckon pmi will improve them. As long As I have an iqos and heets i will never smoke a cigarette again.

    1. Hi there Leon,

      Many thanks for your feedback! You are absolutely right heat not burn will only get better as improvements are made with every subsequent release. 🙂


  8. Hi, I’ve been using Heets for a month now and think they are great. My only concern now is having read the small print it is not recommended for diabetics or heart conditions, which I suffer with. Can someone explain why, compared to normal smoking?
    Thanks, Tony

    1. Hi there Tony.

      Many thanks for your comment. That will be the nicotine, a lot of the harmful chemicals found in traditional cigarettes are absent or of a much lower quantity in the HEETS. It’s the combustion that really does the damage but as said before it is the nicotine you need to be concerned about.

      I am not a doctor but would suggest that you have a word with your local GP.


  9. Been using iqos and turquoise heets for 7 months now. I would like to know if the menthol flavor is more harmful than the others? I wonder because regular cigarettes with menthol are more damaging, so I’m interested in doing the same for heets?

    1. Hi there Lejla,

      I must admit I am not aware that regular menthol cigarettes are more damaging than regular cigarettes, I haven’t personally seen any evidence of this, but I can confirm that our menthol HEETS are no more damaging than the regular tobacco ones.*

      * Remember that by heating the tobacco instead of burning it you are already cutting down on many harmful chemicals that are found in traditional cigarettes.

      Many thanks,


    2. Hi, Lejla. Regular cigarettes with menthol are NOT more damaging, and neither are menthol HEETs. Hope that helps!

  10. Hi there,
    I’m using Heets for 3 weeks and I really appreciate it. However I experience allergies with the Amber label, while the Yellow one is just perfect.
    Anyone can say what possible different ingredients might give me allergy into Amber label ?

    1. Hi there Francois,

      As far as we are aware the ingredients will be exactly the same with the only thing being different is the actual tobacco strength, Amber is quite a bit stronger than the Yellow in terms of flavour as you will probably know having vaped both flavours. So sadly I cannot offer an answer as to why the Amber is giving you some kind of allergy.

      I will do some research and get back to you.

      Many thanks,


  11. I have been a smoker for 40+ years I came across a advertisement for the IQOS 3Duo thought I would give it a go and since I received it I’ve not smoked a normal cigarette this is the best thing ever I absolutely love it

  12. Hi.
    1. Does the iqos heets contwin any tar like normal cigarettes do?
    2. Compared to cigarettes, what amt of chemicals do iqos heets contain?
    3. If cigarettes burn at abt 600degrees, what is the temperature at which the iqos heets operate at an optimum?

    1. Hi there Collin,

      Please see this blog post for lots of information on how heat not burn compares to regular smoking:

      And here is another excellent post by one of our authors when he went to visit PMI’s factory in Neuchatel:

      And as for answer to question 3, the IQOS heats the tobacco up to around 350°C which is enough to create a vapour but not enough to burn it (hence the name heat not burn.) Most of the damage done to a smokers health is caused by the burning tobacco.

      Hope this helps,


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