• Positive

    • Contains a huge amount of ingredients
    • Some strong T boosters, estrogen blockers and HGH stimulators
    • Available at a reasonable price
  • Negative

    • Uses proprietary blend so doses unknown
    • Special formula delivery system a gimmick
    • Ingredients a mixed bag
    • So much included volume of somethings will suffer
  • Ingredients :
  • Price :
  • Trust :
  • Testimonials :
  • Company :
  • Overall Score: 7.5/10

ISA-Test GF Review

ISA-Test GF is a herbal T boosting supplement from the company iSatori, which caught our eye for a number of reasons.

Firstly it aims to not only stimulate T and lower estrogen but also promote the production of growth hormone. 

The second thing that stood out is just how many ingredients are in this ISA-Test GF. We’re talking in the teens! Most of them are in proprietary blends which is disappointing, but by casting its net so widely you hope there’ll be at least some worthwhile components.


The last thing to note about ISA-Test is its supposedly revolutionary method of absorption. The company use something called Rapid Bio-Diffusion Delivery Technology, which is basically the miniaturisation of nutrients to help assimilation and start the booster working within 30mins.

We’ll touch on this later, but before we worry about how fast it works, the key question, does it work?

How Does ISA-Test GF Work?

Before we attempt to pick our way through ISA-Test GF’s proprietary blends, let’s first deal with the ingredients given their own independent volume.

Vitamin C

The benefits of vitamin C are highly publicised. May have some anti-oxidant effects which help testosterone indirectly, but other than that much more geared towards general good health. Not exactly an essential inclusion.

Vitamin B6

Much more relevant choice here; vitamin B6 has been found to significantly slow the production of estrogen and minimise it’s effects, leaving our hormonal balance tipped generously in favour of testosterone. 7mg is a good dose too.


Magnesium is great for freeing up to 60% of our testosterone which may be inhibited by Sex Hormone Binding Globulin. Once released by magnesium, you’ll have much more free test to put to use in the gym or bedroom. 300mg is a strong amount and has every chance of getting the job done.


Zinc is really essential. One of the best minerals for the promotion of luteinizing hormone, which governs the release of testosterone, our androgen levels can drop drastically if we’re deficient. Side effects are a possibility if a supplement gets carried away, but 20mg here is fine.

So now we come to the first, and largest, proprietary blend in this product containing a total of 1714mg worth of components.

Tribulus Extract

This is a disappointment. Once considered a potent testosterone booster, this has now been largely discredited by clinical trials which have repeatedly found little or no effect on test levels. Despite this some supplements, this one included, inexplicably still favour it over the much more scientifically robust and effective D-Aspartic Acid.

Epimedium Extract

More commonly known to many as Horny Goat Weed, this staple of alternative medicine has a solid track record of raising testosterone in animals under clinical conditions, but corresponding studies on humans are less common and conclusive. Still a bit of a mystery then, doubly so here as it is part of a blend and we don’t know its dose.

P-450 Estrogen Inhibitor

An estrogen inhibitor made up of flavonoids, 50% of which we are told is hesperidin. Hesperidin is found in orange peel and does appear to be an aromatase inhibitor. It’s had some success regulating the female hormone in rats but doesn’t have the human study background of a B6. Results on rats were also brought about with very specific doses and that’s one thing we don’t have here.

Tongkat Ali Extract

Otherwise known as Longjack, where this ingredient really comes into its own is as a libido enhancer, which, to be fair is something this product promises to do. One study showed cyclists experienced an increase in testosterone taking this, but besides that the evidence as a test booster is weak.

Ajuga Turkestanica Extract

A plant containing Turkesterone, which is an ecdysteroid capable of producing testosterone like effects in the body, though according to the one human study, without actually effecting levels of the hormone itself.

Grape Seed Extract

Has been shown in clinical studies to protect against damage to the testicles brought about by toxins like alcohol, which adversely affect our ability to produce testosterone. By limiting this impairment, grape seed extract might help our hormone levels remain healthy for longer.


Fenugreek is a strong choice because it not only enhances sex drive but also controls insulin levels and regulates Sex Hormone Binding Globulin levels. Both of which can severely hurt how much effective test is in our system if left to get out of control.

Rhaponticum carthamoides extract

What little research has been done on this ingredient hasn’t yielded great results. There doesn’t appear to be any androgen activity provoked by it at all. That said, it also so contains ecdysterone so may bring about some testosterone like effects.

The second proprietary blend is called Somatrin and contains 325mg in total

Velvet Bean Extract

Perhaps better known as Mucuna Pruriens, this ingredient has a wealth of benefits. It is known to raise human growth hormone and testosterone significantly, in the case of the latter by as much as 27.3% according to one study. Over and above that though it also reduces the stress hormone, cortisol, leading not only to higher test but improved mood.

Nettle Extract

This is another strong addition as it attaches itself to SHGB in place of testosterone, leaving more of the hormone flowing free for you to put to good use. Besides that though it also gives testosterone a boosting by regulating oestrogen through use of beta-sitosterol.


Melatonin is the hormone your body uses to ensure deep, restful sleep. Supplementing it correctly can help you achieve this consistently, helping to improve recovery times after exercise and overall mood, day to day. Although it’s in a blend and we don’t know the exact amount, users regularly mention this product helped their sleep.

The last blend is 100mg of ISAFLOW

Butchers Broom Extract

Clinical trials have shown that where this ingredient can really help is in stimulating better blood flow and calming inflammation. This can aid a number of things such as energy levels, erection strength or recuperation time after exercising. No direct effect on testosterone however.

Hesperidin Methyl Chalcone

Hesperidin again, but this time in a more absorbable form, it has the ability to strengthen the walls of blood vessels and capillaries, which is why it’s often used in beauty treatments to cut down on unsightly blotches on the skin. Likely here though as an attempt to further bolster strong blood flow round the body.

How Do I Take It?

ISA-Test recommends you take 4 capsules an hour before you work out and on non-training days, 4 one hour before you go to bed. It also directs that that you continue taking the product for 8 weeks, before taking a break for a month and then starting another bottle.

4 is a good number of capsules to be taking, that’s right on the money for a good effective/convenience balance, however we’re not crazy about having to take all our serving at once. A much better way of doing it to guarantee sustained effects is to space your portions out over the day. Also the 8 weeks on, 4 weeks off thing can be fine for those used to keeping that kind of schedule with supplements, but for those just starting out, an option you can simply make part of your uninterrupted, on-going routine may be preferable.

Side Effects

We haven’t found any reports of side effects, which squares with what we would expect from most of these ingredients.

Where Can I Get ISA-Test?

ISA-Test is currently available from a number of online retailers including Amazon.com and Bodybuilding.com. It typically retails around the mid-range $30 mark. It is not currently available in the U.K or Europe.


The Scores

Ingredients (6/10) – With so many ingredients, ISA-Test GF would be in real trouble if it couldn’t manage a few standouts, and sure enough they’re here. Assuming they’re dosed highly enough Mucuna Pruriens will help with HGH and testosterone, B6 will keep your estrogen in check, fenugreek should give your libido a kick and help get the hormones flowing and nettle root ought to keep free testosterone up and aromatase down. But because of the way this supplement is put together there are big question marks over some of the ingredient (not least trib) and nearly all of the amounts. Not useless, but not as useful as it could be.

Price (7/10) – The $40 it retails at on the official site is steep for what you’re getting but shop around and find it in the low 30s. Then there’s so much packed in here that the good starts to outweigh the bad in terms of value.

Testimonials (6/10) – There is good depth in testimonials on the iSatori site across the range generally. Mainly from associated athletes, but the ISA-Test section only really offers glowing statements drawn from around the web. The reviews of this product we saw from further different retailers obviously varied in usefulness, but were broadly positive with restful sleep and heightened energy a theme. Again, no mention of it kicking in within 30mins.

Trustworthiness (8/10) – All of iSatori’s supplements look to be manufactured in alignment with GMP regulations, so we’ve no reason for concern. We were also unable to uncover any major customer service scandals and only didn’t award full marks due to the use of proprietary blends and some questionable ingredients.

Company (10/10) – We can’t fault iSatori here. Incredibly professional website, with plenty of info on their supplements and history of the company, alongside exercise plans, dietary advice and athlete profiles. They have a range of products available besides testosterone boosters, many of which are very popular.


ISA-Test GF is a bit of a trade-off between quality and quantity, and while the quantity doesn’t quite match the quality, there’s at least one proven ingredient for each of the areas ISA-Test claims to help.

There’s libido and energy stimulators, as well as testosterone and Human Growth Hormone boosters. Still, too many misguided and unestablished choices stop us heartily recommending this supplement, there are better options.

However … it is reasonably priced considering how much you get and if trouble sleeping is affecting your performance this might be a good choice. Restful sleep is one area where ISA-Test regularly gets positive reports, and we’d go for this over ZMA every time.

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