MuscleTech Gakic VO2 Max SX-7 Review
Gakic VO2 MAX SX-7 is presented by MuscleTech as a non-stimulant pre-workout designed to increase strength. The product is sold as 128 tablets, with 16 servings and a dose of 8 tablets. The page says it provides a clinical dose of Terminalia arjuna and is formulated to give immediate and significant gains in strength and muscular endurance, with significant improvements in VO2 max and absolute power. It states the product lets users perform the hardest workouts without the need for creatine or stimulants. The page describes an 8-week clinical study on men in which the Terminalia arjuna dose produced a significant 4.9% increase in VO2 max, and subjects increased absolute average power by 3.6%, measured through interval jumps and a subsequent power calculation. The listed effects are an immediate 22.5% strength increase, TERMINALIA added for significant VO2 max gains, improved work after the first dose, a scientifically tested 21% increase in endurance, and zero stimulants. Usage is 8 tablets about 30 to 40 minutes before physical activity. The listed nutritional values show calcium 350 mg (35% daily value), sodium 25 mg (1%), glycine, L-arginine HCl and calcium ketoisocaproate 10,202 mg, and Terminalia bark extract 500 mg.
Study, Trial or Testing Result Summary
Members Only13 human studies · 4 improved
The main part of this product is a 10,202 mg blend of glycine, arginine and calcium ketoisocaproate, and no study findings for that blend were given, so its effect on energy is unknown. Terminalia arjuna bark extract is present at 500 mg, above the 400 mg used in studies. In 72 healthy adults, 400 mg a day for 8 weeks raised the heart's pumping capacity more than placebo and lowered fatigue scores from where people started [1]. In 32 young men who exercised regularly, the same amount for 56 days improved the heart's pumping capacity and lowered tiredness after exercise more than placebo [2]. Both trials were small and used one branded extract. Calcium is 350 mg per serving, reaching the studied range at three servings a day. Support for calcium and energy is weak. One trial in young women with premenstrual syndrome found less early tiredness [3]. Another trial in older men could not separate calcium from protein, vitamin D, training and testosterone [4]. Other trials found no gain in oxygen uptake [5], aerobic capacity or time to exhaustion [6], or mood [7]. Animal and cell studies are never counted.
See all 13 studies →Hide the studies
- A review of 32 studies of phone apps for osteoporosis self-management found no clear effect on fatigue or on calcium intake; this was not a test of calcium supplements.Digital Health Technologies for Long-term Self-management of Osteoporosis: Systematic Review and Meta-analysis.
- In 148 men aged 70 and older, 20 weeks of calcium, vitamin D and protein with strength training and testosterone reduced tiredness and improved chair-stand performance compared with no intervention, but calcium's own effect cannot be separated.Beneficial effects of exercise, testosterone, vitamin D, calcium and protein in older men-A randomized clinical trial.
- In 94 adults, a 4-week high-calcium diet was compared with a DASH-type diet and the abstract reports mood benefits only for the low-sodium, high-potassium diet, not for the high-calcium diet.Dietary electrolytes are related to mood.
- In 72 healthy adults aged 30-70, 400 mg a day of Terminalia arjuna bark extract for 8 weeks raised the heart's pumping capacity more than placebo (6.28% vs 0.24%) and lowered fatigue scores by 22.52% from baseline.Effect of E-OJ-01 on Left Ventricular Ejection Fraction and Myocardial Oxygen Consumption: A Randomized, Double-Blind, P…
- In 32 healthy young men who exercised regularly, 400 mg a day of Terminalia arjuna extract for 56 days improved the heart's pumping capacity more than placebo and lowered post-exercise fatigue ratings more than placebo.Effect of E-OJ-01 on Cardiac Conditioning in Young Exercising Adults: A Randomized Controlled Trial.
- In 24 adults with low parathyroid function, one month each of calcium citrate and calcium carbonate showed no difference in quality of life scores; the abstract does not report a fatigue difference.Calcium Citrate Versus Calcium Carbonate in the Management of Chronic Hypoparathyroidism: A Randomized, Double-Blind, Cr…
- In 18 trained adults, three days of hydrogen-rich calcium powder lowered breathing rate and blood pH during exercise but did not change oxygen uptake compared with placebo.Application of Molecular Hydrogen as an Antioxidant in Responses to Ventilatory and Ergogenic Adjustments during Increme…
- In eight men doing calf contractions to exhaustion, calcium carbonate used as the control had no effect on time to fatigue, which was similar to the acid and alkaline trials, showing that changing muscle pH did not alter fatigue.The effect of pH on fatigue during submaximal isometric contractions of the human calf muscle.
- In young women with premenstrual syndrome, 500 mg of calcium carbonate twice daily for 3 months reduced early tiredness compared with placebo.Effects of calcium supplement therapy in women with premenstrual syndrome.
- In 11 male runners, 4 days of calcium phosphate loading did not improve maximal aerobic capacity or time to exhaustion compared with placebo.Phosphate supplementation, cardiovascular function, and exercise performance in humans.
- In 65 adults with self-reported gluten sensitivity on a gluten-free diet, average calcium intake from food was 695 mg a day, below recommendations, and energy was not studied.Dietary and symptom assessment in adults with self-reported non-coeliac gluten sensitivity.
- In adults with hypophosphatasia, a higher calcium to phosphorus intake ratio was associated with more tiredness and fatigue, and very high or very low calcium intake was linked to more symptoms, based on a 7-day diary.Mineral Intake and Clinical Symptoms in Adult Patients with Hypophosphatasia.
- A survey of U.S. adults found that drinkers had higher energy intake than non-drinkers, but their diets were less nutrient dense, including for calcium; the survey did not test calcium for energy.Alcohol consumption and nutrient density of diets in the Nationwide Food Consumption Survey.
Review Totals and Summary
Members Only44 reviews
The store shows 5 ratings in total (all on MuscleTech Store, muscletech-store.it), and the themes below come from the written reviews that could be read on its page, which numbered only three, all dated 2015. Because so few written reviews were readable, this is a small sample and should be treated as such rather than as a reliable pattern. What buyers praise: The feedback is positive throughout. One reviewer says the new Gakic improved again on taste and solubility, and recommends it to everyone. Another says they took it straight after training and found that it acts quickly. The third says only that they tried it and had very good results, without saying what those results were. Complaints: None appear in the readable reviews. No pattern of criticism shows up on this page, though with only three reviews that says little about how the product would fare more broadly. Taste, form and mixing: Taste and solubility are the main specifics. One reviewer treats both as improvements over earlier versions of Gakic. Nobody describes a flavour in detail, and there is no mention of how the tablets themselves look or feel to take. Timing and use: Timing of use is the only practical detail given. One reviewer took it right after training and reports that it works quickly. No dosing, stacking or other usage advice appears. Who it seems to suit: The reviews point to people who train and want something to take around their workouts, particularly post-workout. One reviewer recommends it to everyone, but the reviews do not describe the buyers' goals, experience level or training type. What the reviews do not cover: They do not discuss strength gains, VO2 max, side effects, or value for money, so nothing can be said about those from this page. The store itself notes that reviews are individual customer experiences that may differ from person to person. Other product forms: The summary mentions no gummies, capsules or powder, so nothing had to be left out on that account. This write-up concerns the tablets only. Overall, the readable feedback is warm but brief: pleasant taste and solubility, quick-acting when taken after training, and a satisfied buyer reporting very good results. Anyone weighing the product should look for more detailed reviews elsewhere, especially on effectiveness, tolerance and price.
Biohacker Summary
Members Only10 of 10 recommend it
The panel is split on calcium, the main ingredient, and only a few of the ten clearly back taking it as a supplement. Three of them recommend it for bone health, one suggesting 1,000 to 1,200 milligrams a day as calcium carbonate or calcium citrate, and another taking it daily in a mix, while one takes a calcium and magnesium pill and another suggests calcium citrate with high oxalate meals. Four lean toward getting calcium from food such as sardines, dairy, kale and leafy greens, and several warn that supplements may raise heart, artery or kidney stone risk, that calcium alone will not fix bone loss, and that it needs vitamin D, vitamin K2 and magnesium alongside it. One tells people to stop calcium supplements as part of a protocol, and another says calcium and magnesium should not be taken together, while a third suggests a two-to-one ratio of calcium to magnesium.
See all 10 biohackers →Hide the biohackers
Dr. Eric Berg · Calcium · warns
- Warns that bone loss cannot be fixed with just calcium, as bone is primarily collagen with other essential minerals.
- Dr. Berg includes calcium carbonate among the synthetic supplements to avoid.
- Warns against calcium carbonate, also known as limestone, stating that while it lowered hip fractures in a study, it also increased kidney stones and is not good for arteries, requiring the body to work hard to use it.
- Notes that tannins in tea bind calcium, blocking its absorption.
- Indicates that horizontal thin white lines near the base of the nails are indicative of low calcium.
- Warns that calcium carbonate can build up in the arteries and kidneys and increase the risk of a heart attack.
- Dr. Berg mentions that fermented dairy contains vital nutrients, including calcium.
- States that calcium and magnesium are intrinsically linked and work in combination with vitamin D to support the body's calcium balance.
- Explains that calcium triggers muscle contraction, while magnesium is needed to relax the muscles afterward.
- Warns that too much calcium can cause high blood pressure by causing arterial contraction.
Siim Land · Calcium · neutral
- Lists dairy and sardines as sources of Calcium.
- Notes that Boron reduces calcium/magnesium loss.
- Recommends a high calcium intake for bone health.
- Places calcium supplementation in the 'bad tier' due to its association with increased cardiovascular events, recommending dairy or bones as easier ways to get calcium, though it can be useful for postmenopausal women with low bone density.
- Mentions that eating enough calcium matters for bone density, but states that it alone won't transform bone density.
- Warns that calcium is linked to a higher risk of heart disease, though people with low calcium status and intake can take it safely.
- Warns that calcium supplements increase the risk of heart disease by raising blood calcium levels too high, leading to hypercalcemia and more calcium being stored in the arteries, and also increase the risk of arrhythmias.
- Warns against calcium supplementation for most people due to its association with increased cardiovascular events, but notes it can be useful for postmenopausal women with low bone density who don't consume dairy.
- Discusses Calcium as a supplement.
- Recommends consuming calcium from dairy, tofu, leafy greens, and bones, as it is a key nutrient required for ATP synthase in mitochondrial energy production.
Thomas DeLauer · Calcium · neutral
- Notes that milk contains 120mg of calcium, while sardines contain 351mg, highlighting a 3x difference.
- Recommends getting calcium, along with vitamin D, zinc, and magnesium, from foods like sardines, as they are important for inflammatory pathways in the gut.
- Explains that eating sardines with their soft bones provides a serious hit of calcium, which is a perfect combination for bones and may contribute to satiety.
- Mentions that magnesium and calcium should not be taken together as they cancel each other out.
- Tries to get multivitamins without calcium or with a low amount, as he believes supplemental calcium impacts the absorption of other vitamins and minerals and is not as beneficial as hyped. He cautions against it for most people due to the risk of coronary artery calcification.
- Recommends getting calcium from dairy sources like milk, yogurt, kefir, and cheese in the morning to support neurotransmitter synchronization crucial for deep and REM sleep, noting that low dietary calcium is linked to insomnia.
- Warns that calcium competes with magnesium for the same absorption channels, advising to separate magnesium intake from calcium supplements or dairy by at least an hour or two.
- Recommends providing the body with adequate dietary calcium, not a calcium supplement, to ensure a clean, strong spark for efficient insulin release.
- Warns that calcium and magnesium should not be taken together as they cancel each other out, though some products use delayed absorption to mitigate this.
- Warns that most people consume too much calcium relative to magnesium, which can disrupt the balance needed for proper bodily function, comparing it to an electrical circuit.
Dr. Mark Hyman · Calcium · recommends
- Notes that calcium is in bones but is also essential for nerves, muscles, and the heart, and low levels can affect muscle function and heart rhythm.
- States that green leafy vegetables are great sources of calcium.
- Notes that calcium needs are lower than advertised and that stress, soda, and excess sugar can drive calcium loss.
- Does not prescribe calcium supplements at all, teaching people to get it from whole foods instead, because calcium supplements don't work for building bones or preventing fractures, and it's bone quality, not density, that matters.
- Warns that acid blockers inhibit calcium absorption.
- Lists calcium as another important nutrient that people can be tested for and measured.
- States that high doses of calcium supplementation in the elderly were not really impacting bone density, as osteopenic patients still became osteoporotic.
- Warns that meds (meds) impair the absorption of calcium, which increases the risk of hip fractures and osteoporosis.
- Recommends calcium citrate, about 600 milligrams a day, for bone health, noting that much can also be obtained from diet through leafy greens, sesame seeds, tahini, and chia seeds.
- Dr. Hyman notes that while calcium deficiency is not common in terms of blood levels, insufficient intake can lead to osteoporosis as the body pulls calcium from bones. He advises caution with calcium supplementation due to potential heart issues.
Dr. Rhonda Patrick · Calcium · neutral
- Mentions that kale delivers calcium, a micronutrient many diets fall short on.
- Notes additional gaps in calcium.
- Reports that alcohol use disorder is associated with a 20-50% greater prevalence of Calcium deficiency.
- Around 38% doesn't meet the requirement for calcium.
- Takes a calcium-magnesium pill because he believes people tend to be short of both and that the body cares about the ratio of these similar molecules.
- States that 1,000 milligrams of calcium per day is the recommended intake for bone density, and supplementation is an option if this requirement is not met.
- Takes a calcium, vitamin K2, and vitamin D combination supplement in the morning, providing about 600 mg of calcium and another 1,000 IUs of vitamin D.
- Dr. Rhonda Patrick discusses calcium needs.
Dave Asprey · Calcium · neutral
- Notes that when energy intake is too low for training demand, nutrient intake often falls short, especially for calcium, which is associated with reduced bone health.
- Explains that calcium provides the raw material for bones, but it isn't a standalone input and needs a whole system to be effective.
- Notes that people take calcium for their bones.
- Warns that taking calcium without vitamin D, A, and K2 can lead to calcium going into tissues, causing bone spurs and other issues, and recommends a two-to-one ratio of calcium to magnesium.
- Recommends taking calcium citrate during a high oxalate meal to bind the oxalate in the gut.
- Notes that people often take calcium for bone health.
- Believes calcium supplements are overrated, as most people need more vitamin K2 and vitamin D instead.
- Advises taking iron and calcium separately because they will bind together.
- Takes extra calcium to help deal with the burden when eating chocolate or anything with higher levels of oxalates.
- Discusses calcium citrate as a counter to oxalate crystals, specifically when consumed through dairy, but questions if it's the primary form of calcium in dairy.
Ben Greenfield · Calcium · neutral
- Is considering whether he needs a calcium supplement because lead can displace calcium in bones, affecting bone strength.
- Mentions calcium as a common deficiency.
- Recommends adequate intake of calcium for bone strength.
- Is using calcium chloride mixed with PRP before injecting for the P-shot.
- Advises people to stop taking calcium supplements as part of the Root Cause Protocol.
- Warns that in high doses, calcium without the right cofactors can raise cardiovascular risk by contributing to arterial calcification instead of bone strength, and may increase the risk of osteoporosis.
- Explains that 10X separates calcium and zinc into different micro beads, releasing them at different rates and locations in the digestive tract to prevent competition and optimize absorption.
- Covers calcium as a key supplement for kids.
- Warns of calcium deficiency on a carnivore diet, as there is not an appreciable amount in meat, and recommends eating fish with bones or taking a calcium supplement or bone mineral matrix.
- Notes that excess calcium intake can contribute to calcium buildup in the arteries.
Peter Attia · Calcium · recommends
- Recommends calcium as one of the 'big three' micronutrients for bone health, suggesting a daily intake of 1,000 to 1,200 milligrams, which can be supplemented with calcium carbonate or calcium citrate.
- Explains that bone is 50 to 70% mineral, predominantly calcium, and that virtually all of the body's calcium is contained within bone, making bone important for calcium homeostasis.
- Recommends calcium for bone health, stating that teenagers probably need about 1000 milligrams a day.
- Discusses bone acting as a reservoir for calcium and how resorption and formation release calcium into the blood when needed.
- Notes that bone is 50 to 70 percent mineral, with calcium being the predominant mineral, and virtually all of the body's calcium is contained within bone.
- Recommends getting about a gram of calcium a day from organic bone meal, which provides calcium hydroxyapatite, the form humans are meant to consume.
- Suggests that calcium is one of the other signals involved in regulating mitochondrial number, beyond AMPK activation.
- States that in postmenopausal women not on estrogen, calcium and vitamin D have no protective effect against hip fracture because the problem is not the shell of the bone, which is fed by calcium and vitamin D, but the internal girder network.
- Notes that compelling evidence links calcium to reduced risk of osteoporosis, which can impact mortality from specific causes.
Bryan Johnson · Calcium · recommends
- Recommends calcium as a mineral that, along with phosphorus, magnesium, and boron, is deposited to fortify the bone structure after the collagen scaffold is in place.
- Agrees that a little extra calcium is probably okay, especially for women, to really hit home for bone mineral density.
- Recommends prioritizing calcium intake for postmenopausal women to help maintain bone density and reduce the risk of osteoporosis.
- Bryan Johnson takes Calcium daily as part of his Longevity Mix, which supports healthy bones and teeth.
- Recommends continuing with calcium to support bone health during the follicular phase.
Andrew Huberman · Calcium · neutral
- Discusses "hard water" and the role of magnesium and calcium in cardiovascular health.
- Adequate intake of calcium is vital for bone health.
RAL Summary
Members OnlyTier 4 for Energy
Two small placebo-controlled trials support Terminalia for lower fatigue [1][2], and calcium has mostly null results. With no counted reviews and no evidence for the main blend, the evidence stays emerging.
Take 3 servings a day (24 caplets) to match the dose that worked in the studies.
- Emerging: not enough evidence to rank higher yet.
Where the evidence disagrees: 9 of the 13 human studies found no effect.
More Details
Members OnlyBody systems · Combine with · Possible side effects
Body systems: Cardiovascular system, Musculoskeletal system
Combine with: For this product's actual purpose (energy and endurance), consider creatine monohydrate for power output and strength, citrulline malate for pump and blood flow, electrolytes (sodium, potassium, magnesium) for hydration, and L-theanine to smooth out caffeine jitters. If the real goal is blood pressure support, use a different approach: magnesium, potassium-rich foods, CoQ10, omega-3 fish oil, beet root nitrate, hibiscus, or garlic extract, and talk with a doctor before using stimulants like caffeine if you have hypertension or are on meds.
Possible side effects: No major side effects reported.
Supplement Facts
Calcium 350 mg · Blend 10202 mg · Terminalia bark extract 500 mg
| Calcium | 350 mg | |
| Sodium | 25 mg | |
| Blend (Combination) | 10,202 mg | † |
| Terminalia bark extract | 500 mg | † |
Other ingredients: Microcrystalline Cellulose, Carboxymethylcellulose Sodium, Hydroxypropyl Cellulose, Hypromellose, Magnesium Stearate, Stearic Acid, Polyethylene Glycol, Titanium Dioxide, Silicon Dioxide, Natural and Artificial flavor, Talc, Acesulfame-Potassium.
Directions: Directions: Take 1 serving (8 caplets) 30 to 45 minutes before your workout. Read the entire label before use and follow directions provided. This bottle provides a 4-week supply if you work out 4 times per week.
Barcode (UPC) 631656604993 · Label source: NIH label database · Report a label change
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Graded November 3, 2026 by the Reverse Age Lab evidence engine, from human studies, real reviews and our biohacker panel. How we grade. Is this medical advice? No. Rala organizes the published evidence; go over any change with your doctor, especially if you take meds.
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