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FLEX Stack®

FLEX Stack®


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Perfect For

Versatile Testosterone Boosting Stack
  • N-TEST 600®:
    • Lean Muscle Mass, Strength and Hardness (Testofen® + Tribulus)
    • Estrogen Blocker (Hesperidin + Transresveratrol)
    • Increased Libido (Testofen® + Tribulus)
  • Z-TEST®:
    • Estrogen Blocker (Tribulus + Oat Straw + Indole-3-Carbinol + Diindolymethane (DIM) + Chrysin)
    • Boosts Natural Growth Factors (Tribulus)
    • Promotes Restful Sleep (L-Dopa + Melatonin + Chamomile)

Daytime and Nighttime Natural Testosterone Stack

The FLEX Stack® is a dual attack anabolic monster designed to overload the system with a relentless and constant 24-hour barrage of muscle-yielding testosterone, to facilitate extreme muscle growth and maximize anabolic results.* Powered by N-TEST 600®, an all-natural testosterone booster that contains the clinically-studied ingredient Testofen® to increase free testosterone levels by up to 98%, the FLEX Stack® maximizes your physiological levels of testosterone to help support greater muscle strength and size.* Phase 2 of FLEX Stack’s anabolic mayhem is Z-TEST®, a nighttime anabolic catalyst that increases natural testosterone levels, blocks estrogen, increases natural growth factors (GH), and promotes a more restful, restorative sleep.* When these two are used in tandem, they help create an extreme anabolic environment that drives dynamic results.*

Natural Daytime Testosterone Booster:

N-TEST 600® is fully jacked with 600 mg of Testofen®, the clinically studied amount necessary to increase free flow testosterone levels up to 98%†. Because N-TEST 600® increases testosterone levels naturally versus synthetically, it provides all the positive bodybuilding results without the negative androgenic and estrogen-related side effects.*

4 Key Ingredients:

N-Test 600® includes Testofen® and Tribulus Terrestris – key anabolic-inducing compounds, coupled with Hesperidin and Transresveratrol – key anti-aromatase compounds. Synergistically they help to produce extreme and potent results in increased strength, size, lean muscle mass, and muscle hardness.*


Delivered via liquid technology N-TEST 600® includes Bioperine® for increasing the absorption of the mass-building and strength-increasing ingredients necessary to achieve anabolic results.*

Versatile Night-Time Anabolic Catalyst:

Use Z-TEST® in conjunction with any testosterone supplement to fully support and increase anabolic gains. Z-TEST® can also be used alone as a PCT (Post Cycle Therapy) after an intense on-cycle, specifically optimizing healthy testosterone levels during the night-time while also restoring your endocrine system back to its natural homeostasis.*

Anti-Aromatase/Estrogen Blocker:

Z-TEST’s formulation helps block estrogen, which helps to avoid the negative and adverse androgenic and estrogen-related side effects commonly associated with natural or artificial sources of testosterone supplementation.*

Boosts Natural Growth Factor:

Z-TEST® supports the release of more natural growth factor, which the body produces less of with age. Z-TEST® uses these growth factors to increase muscle hypertrophy, support lean body definition, and improve recovery.*

Restful Sleep:

Z-TEST’s formulation also includes ingredients used to promote a more relaxing, restful & restorative sleep to aid recovery.*

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An extract of fenugreek seed containing the steroidal saponins, sapogenins and furostanol saponins, which have been suggested in human studies to raise free testosterone (the biologically active form) and act as important precursors for the synthesis of a number of sex hormones for an increased libido.† Just as important, not only does Testofen® boost free testosterone, but it also aids in fat loss. Participants in a study have significantly raised testosterone, and also didn't gain any weight. Blood Urea nitrogen levels were also significantly reduced after consumption of Testofen®, which shows a reduction in protein catabolism.*

Testofen®, unlike other Fenugreek products available today, contains high concentrations of a specific group of saponin glycosides isolated and characterized exclusively by Gencor scientists. These compounds, called fenusides, are the subjects of ongoing research, which Gencor believes will continue to support Fenugreek's testosterone-promoting benefits. Testofen® is a registered trademark of Gencor Pacific, Inc.

†Effect of Testofen® on safety, anabolic activity and factors affecting exercise physiology. ©Copyright 2008 by Gencor Nutrients, Inc.


Water-soluble citrus bioflavanoid found in oranges and lemons used to boost exercise recovery by interfering with the metabolism of arachidonic acid. This very important compound plays a widespread role in the cell signaling that leads to growth, and for reducing exercise-induced inflammation. It also protects the heart and acts as a strong antioxidant and supports cell integrity and immune system health, possibly protecting against many cancers, including colon, skin, urinary and esophageal cancer.*


Studies show Transresveratrol is effective in combating cancer, obesity, diabetes, and heart disease.* It may also be effective for weight control and for improved sexual health in men. Using transresveratrol on a consistent basis may even increase life expectancy.*


The only product sourced out of piperine to obtain a patented status for its ability to increase the bioavailability of nutritional compounds. Secondly, it is the only source from piperine to have undergone clinical studies in the U.S. to substantiate its safety and efficacy for nutritional use.


A Bulgarian herb used to increase both free and total testosterone levels, and as a result, enhances your muscle building capabilities and sex drive. It is believed that it exerts its effects through an increase in Luteninizing hormone (LH) levels, a hormone that signals the body to increase its testosterone production.*


Indole-3-carbinol occurs naturally in cruciferous vegetables such as broccoli, cabbage, cauliflower, brussels sprouts, collard greens and kale. With powerful antioxidant protection, I3C helps to prevent cellular damage caused by free radicals. In addition I3C can help reduce estrogen levels while maintaining a healthy hormonal balance. I3C is also known to support the liver's detoxification processes as well as normal cellular reproduction.*

Diindolymethane (DIM):

DIM blocks the estrogen receptors activity, and by interfering with them, it helps raise the ratio of testosterone to estrogen. With DIM causing more testosterone to be freed, this means a result in a higher sex drive, better moods, muscle building, and bone-strengthening from workouts. Other possible DIM benefits include: the fat burning and the increase of insulin sensitivity, which can help with the uptake of nutrients overall.*


Believed to be an effective aromatase inhibitor, Chrysin supports decreasing your body’s level of estrogen. It has also been shown to induce an anti-inflammatory effect.*


As a precursor to dopamine, a chemical in the brain that is linked to cravings and pleasure, L-Dopa is used to maintain elevated dopamine levels, helping you to resist the urge to overeat at night. L-Dopa may also be used to trigger production of human growth hormone, which in turn builds muscle and reduces fat.*


Produced by the pineal gland from the amino acid Tryptophan, melatonin helps the body know when it’s time to sleep or when it’s time to wake up. It maintains the Circadian Rhythm of our body, which is the built-in 24-Hour “clock” inside our body. The Circadian Rhythm plays an important role when we should wake up and when we should fall asleep, and melatonin is directly linked. When your surrounding is dark, the body produces more melatonin, and when your surrounding is bright, melatonin is reduced. By increasing melatonin production in the evening, Z-TEST® will help make it easier to fall asleep.*


Used to help relieve stress by inducing a relaxing effect without drowsiness, L-Theanine helps reduce mental and physical stress, improves focus and concentration, and enhances mood. Studies show it helps both reduce the time that it takes a person to fall asleep as well as decrease the number of nighttime awakenings due to its relaxing and tranquilizing properties.*

5-Hydroxytryptophan (5-HTP):

A naturally-occurring amino acid and chemical precursor as well as metabolic intermediate in the biosynthesis of the neurotransmitters serotonin and melatonin from tryptophan. 5-HTP is used as an antidepressant, appetite suppressant, and sleep aid.

Ingredients & Supplemental Facts Label

Ingredients and Supplemental Facts Label

Level 1: Beginner

Anabolic Switch:

Use N-TEST 600® for 2 weeks, then follow with Z-TEST® for 2 weeks. Repeat this process for 8 full weeks.

Advantage: Switching on and off between both products provides a more constant and steady supply of the testosterone needed to achieve and sustain muscular gains over the course of 8 weeks. It also allows the body to maintain a more natural state of homeostasis, to help avoid adverse androgenic/estrogen-related side effects.*

Level 2: Intermediate

Anabolic Shift:

Use N-TEST 600® alone for 4 full weeks, then follow up with Z-TEST® for 4 weeks.

Advantage: Flood your system with an onslaught of testosterone to maximize full anabolic results in a short time frame. Following with Z-TEST® to improve recovery, and to also restore your body’s natural testosterone back to normal levels. This staggered, dual attack TEST approach provides the positive anabolic muscle gains without the estrogen-related side effects.*

Level 3: Hardcore

Anabolic Mayhem:

Use N-TEST 600® and Z-TEST® together daily for 4 intense weeks.

Advantage: Overload your system with a relentless and constant 24-hour barrage of muscle-yielding testosterone to build more muscle, spike performance, and maximize anabolic results. This aggressive approach creates an environment of anabolic mayhem that takes a hold of your system quickly, to produce extreme results in an accelerated amount of time.*


N-TEST 600®: KEEP OUT OF REACH OF CHILDREN. Consult with your physician before using this product. Do not take this product if you have a medical condition including, but not limited to, diabetes, heart disease, psychological disorder, prostate hypertrophy or hormonal abnormalities. Consult with your physician if you are taking antidepressants, MAO inhibitors, or other prescription drugs. This product should not be used by pregnant or lactating women. Not intended for use by persons under the age of 18. WARNING for California residents only: This product contains a chemical known in the state of California to cause birth defects or other reproductive harm. Do not exceed recommended dose. Do not use if tamper resistant seal is broken. STORE IN A COOL, DRY PLACE, AND AVOID EXCESSIVE HEAT.

Z-TEST®: KEEP OUT OF REACH OF CHILDREN. Do not exceed recommended dose. Not intended for use by persons under the age of 18. For adult use only at bedtime. This product is not to be taken by pregnant or lactating women. This product is not intended for use by those with a serious medical condition. Consult your physician prior to use if you are taking OTC, prescription medication (including but not limited to MOA Inhibitors), or other dietary supplements. Do not use in conjunction with alcoholic beverages, when driving a vehicle, or while operating machinery. Do not use if tamper resistant seal is broken. WARNING for California residents only: This product contains a chemical known in the state of California to cause birth defects or other reproductive harm. STORE IN A COOL, DRY PLACE. AVOID EXCESSIVE HEAT.

Filter Reviews

Average Rating:
based on 5 reviews

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14:37 (GMT)
Best gains i've had with ANY product

  • Best gains i've had with ANY product

    Product: PMD Flex Stack
    Posted By: C.J. Biagioli
    I'm a very hard gainer, I eat tons and tons of calories a day and nothing seems to make a difference for me. the Flex Stack along with Amplify XL and ACG3 worked wonders for me and I added great gains!

    Effectiveness: 5/5
    I had been using the Amplify XL and ACG3 for about 2 weeks before i started on the Flex stack. with the 2 i was already seeing great gains but once i added the Flex stack to my arsenal it really took off. The N-Test 600 took only 2 days to kick in. once during my workouts and i felt stronger immediately and honestly couldnt believe i was able to hit the weights i was putting up because i had hit a plateau for such a long time. My lifts consistently went up each week on which ever body part i was exercising that day. The Z Test was awesome as well because with school, work, and going to the gym i typically was depleted through the day, but with the addition of the Z test i feel asleep shortly after taking it and had tons of energy throughout the day and i rested so well that half the time I actually woke up before my alarm ever went off, so I know it got me into my deepest REM. Another great thing they you look for with any test boosting supplement is I had zero side affects! No added aggression, acne, breast enlargement, etc. All in all if you are in need of a supplement to help with added strength gains and add some substantial size to your frame, the flex stack is what you need!
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14:05 (GMT)
crazy gains with this stack!

  • crazy gains with this stack!

    Product: PMD Flex Stack
    Posted By: JBrezenski
    This stack is amazing! I took the original "Flex Stack" and this stuff is unreal! I love the feeling I get from the NTest 600 and can tell a HUGE difference in all my lifts and workouts. The ZTest is good stuff, much better than the previous Nocturnal. If you're serious about making gains, you need to add this into your regimen....you won't be sorry!
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19:55 (GMT)
so far so good!

  • so far so good!

    Product: PMD Flex Stack
    Posted By: Jimmy
    Product works really well when you combine the 2 together. Ztest quickly makes you fall asleep and when you wake up your pretty replenished. Very good pumps with this product as well
    I was skeptical on buying it due to the price hence why i didnt give a full 5 stars

    But warning, this stuff makes you horny as hell!
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19:54 (GMT)
  • Awesome

    Product: PMD Flex Stack
    Posted By: Nick
    This is the 2nd using these....overly impressed!! Great gains.....I would most definitely recommend this system!!! Worth the money for sure!
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19:05 (GMT)
Worth it

  • Worth it

    Product: PMD Flex Stack
    Posted By: N/A
    Just 3 weeks with the flex stack and i'm already seeing great results! Would recommend this stack to just about anyone.
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