Animal M-Stak Review From Universal Nutrition

Universal Nutrition Animal M-Stak Review

Review of: Animal M-Stak

Reviewed by:
On 2017-08-31
Last modified:2019-10-17


A great effort at redefining natural testosterone and hardgainer supplements, but still too underdosed in the right areas to be effective.

I’m going to start this review by declaring some previous biases, in that I think testosterone products are mostly underdosed rubbish, but that I also have massive respect for the Animal brand in general, something my Animal Pak review certainly shows.

So despite some initial hesitation, I decided to put Animal’s M-stak to the test for one full cycle (three weeks on, one week off), and I consciously went in with as little bias as possible.

I’ve now been using the product for the full container cycle of 21 packs (days), so let’s see how it shapes up.

Product overview

M-Stak by Animal (Universal Nutrition) is a natural, non-hormonal supplement designed for hardgainers.

This basically means it will aid your efforts in gaining muscle, just in case you weren’t clear on that from the badass packaging (below).

Animal M-Stak

M-Stak is not strictly just a testosterone booster, as its main function is to increase gains for those who find it hard (ectomorphs, like me).

That being said, many of the ingredients are very similar to what you’d usually find in a testosterone supplement, hence my focus on it in this review.

M-stak comes in Animal’s trademark pill bags (pictured below), so do not try to take these into a nightclub with you, and expect some dodgy looks from airport security.

Animal M-Stak

This also means that if you are someone who can’t swallow pills well, like a tiny child or a small dog for example, then these won’t be for you.


I’m going to tear down the ingredients briefly, to see what has scientific support.

For this I’ve mostly used the excellent which takes an in-depth look at supplements and nutrients to compare research available.

Where there isn’t any research, I’ve simply used the effectiveness section of this review as judgement to whether it worked or not.

Animal M-Stak

There are two sections of M-Stak that contain pretty common and well-researched ingredients, and these are the “anti-catabolic amino complex” and the “energy complex”.

However, I want to say that the “anti-catabolic amino complex” isn’t really going to do much.

You’d need around three grams of leucine to trigger a decent anabolic (growth) response, and here there’s only three grams in total for all six amino acids included.

If you’re looking for anabolic aminos you’d be better off with grabbing straight up leucine or a BCAA blend – or just whey protein.

The “energy complex” contains some decent stimulants, and I can confirm that they are damn strong and will make you feel great without much of a crash.

This is not for the faint-hearted though as there’s the caffeine equivalent of a few shots of coffee in there.

As a side note, the red pill is the one with the stims, so just remove that if you don’t want to take stimulants.

So that leaves us with four more complexes to look at:

  • Natural Flavone/Sterone complex
  • Anabolic Adaptogen Complex
  • Insulin Potentiating Complex
  • M Factor Complex

Right away there isn’t any research that supports the ingredients in the Natural Flavone/Sterone complex.

That’s not to say they definitely do nothing but there’s just no real conclusive studies.

However, the “M Factor complex” is essentially to aid absorption of the ingredients and is pretty well researched.

Other than these, the Adaptogen complex of M-Stak has two ingredients which may help anaerobic capacity (the energy source used during weight lifting) and there seems to be evidence of these being studied and working.

These are the Eleutherococcus Senticosus (ES) and the Muira Puama extracts – adaptogenic herbs.

But we come back to the same problem as with the amino acids.

In the case of ES alone, the recommended dose for performance is 2-4 grams, and we’ve only got one gram for three combined ingredients.

Side note: the pills smell absolutely amazing – I think it’s the herbs, but man they smell damn good!

Which leads us to the last ingredient section, the “Insulin Potentiating Complex” which is evidently supposed to increase the performance of insulin, a traditionally anabolic hormone.

This section does seem to be supported with some quite decent research on insulin, with levels of supplementation recommended at 500-600mg.

So, that’s the ingredients briefly looked at, but how does M-Stak actually perform?


I took this product for the 21 packets in the container, and I was following my usual routine of compounds at low reps and high weight followed by more reps and bodybuilding movements.

My diet was its usual – around 70% clean and 30% filth, with a focus on high protein and plenty of healthy fats.

Bottom line…

I honestly saw no effects from taking this product at all.

The only thing I might have noted was that the stimulant packet is pretty intense, so you can use this pre-workout as a really nice boost.

However, in terms of my gains or (perceived) testosterone levels, there were no real results that I saw.

We could of course argue that 21 days isn’t enough time to see any results, and that we’d need longer on the product to see any real effects, but considering the product is around the £35 mark for 21 days, it’s not unrealistic to expect results after this period of time.

Value for money

I’ve never really recommended testosterone products due to the fact that they often contain hardly any ingredients that are backed by studies, and when they do they are in such low amounts that it’s not worth buying.

With M-Stak, I genuinely think (and perhaps because I’m a big fan of the brand) that Animal have made a product which is edging towards what natural testosterone boosters should be – a supplement that helps you gain muscle in real doses and is broken down into specific formulas.

But what they have made is something that’s just still too underdosed to be effective.

You’d be better off spending the money on some extra whey protein or creatine – stuff that is proven to help muscle gain.


A great effort at redefining natural testosterone and hardgainer supplements, but still too underdosed in the right areas to be effective.

Buy Animal M-Stak

If you still want to give Animal M-Stak a try, you can usually pick it up for the best price here at Amazon.

Over to you

Have you tried M-Stak?

Agree or disagree with my review?

Any other comments or questions?

I’d love to hear from you below!

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  1. Great review.

    Pretty much spot on.

    Here in the States there are tons of T-boosters that are being marketed to men over 40, and they are probably all better than the Animal product.

    The main thing is if the product is made of all natural ingredients, the most you can hope for is to bring your test up to optimal levels.

    You’re not going to get a “steroid like” effect, which is how they were marketed in the 90s.

    You’re right, creatine, whey protein, and glutamine are all proven and not a waste of money.

  2. Great article, very helpful review.

    Should include this T-booster.

  3. Is it only the red pill that can cause insomnia?

    I purchased M-Stak for the 1st time but am reluctant to start the cycle because some report of extreme insomnia.

    I can’t afford to miss out on sleep, for health reasons, and because of my day job.

    If I cut out the red pill will I not have to worry about insomnia?

    1. Yes mate the red pill contains the caffeine and stims.

      Just take it in the morning and don’t have any other caffeine (coffee etc) and you should be fine sleeping.

  4. Hi there… how about testo fuel then?

    Or any you can recommend?

    1. The Animal Stak (without the M) is mainly a test booster while the M-Stak is for me a complete pre workout formula….

  5. Hi.

    What colour of pill is the Turkesterone in?

  6. Thank you for the honest review.

    Sounds like, in a nutshell, this is a caffeine supplement and most if not all of the workout benefit was from said caffeine.

  7. Hello,

    I just bought the product (unfortunately prior to reading this review xD).

    When I looked into forums or even the product official web page, I couldn’t really find any clear instructions on how the pills should be taken, when and how ?

    The only valuable information is that it should be taken 40 mins before training.

    I see there are different colors, should I take them all at once?

    If I need to split, how?

    Also, usually I take 5g of creatine before going to the gym, is it safe to take pills and creatine together?