Purus Labs d-pol™ is a new product designed by PURUS LABS®, which adheres to the established guidelines of PURUS LABS® in terms of including only those ingredients that have been used in human subjects via oral ingestion, and reported to promote favorable outcomes in relation to the target areas of interest (e.g., enhanced exercise performance, increased circulating testosterone—potentially leading to increased lean body mass, enhanced overall health). d-pol™ contains a unique blend of ingredients, each carefully selected for their potential impact on physical performance and human health—included at the precise dosage necessary to promote the desired effect (as supported by peer reviewed scientific evidence obtained from studies using human subjects). The text below outlines the ingredients used within d-pol™, while providing a brief summary of the rationale for use.
Elevating circulating testosterone has been, is now, and will likely continue to be the objective of many hard training athletes. It is well known that testosterone is associated with gains in both muscle size and strength, in addition to having positive effects on several other vital components of human health. One dietary ingredient reported to produce measureable gains in circulating testosterone is d-aspartic acid (DAA). d-aspartic acid has been reported in multiple animal and in vitro studies to be involved in testosterone synthesis, in species ranging from boar (Lamanna et al., 2007a) to lizard (Raucci et al., 2005). It also stimulates the production of other hormones such as prolactin, leutinizing hormone (LH), and growth hormone. Finally, DAA acts as a neurotransmitter/neuromodulator (D'Aniello, 2007)—an effect noted in several studies using animal models and in vitro experiments.
Considering the sound evidence for a role of DAA in testosterone synthesis, a human study was recently performed to assess the effectiveness of oral DAA supplementation with regards to testosterone elevation (Topo et al., 2009). Subjects included 43 men (27-37 yrs), 20 who received a placebo and 23 who received a DAA supplement (3.12 grams of DAA combined with B-vitamins— the same dosage of DAA provided within d-pol™). The supplement was delivered orally for 12 days. Following the 12 days of treatment with the supplement, 20 of the 23 subjects (87%) had significantly higher circulating LH levels, with an average increase of 33%. With regards to circulating testosterone, 20 of the 23 subjects (87%) had significantly higher values at day 12 compared to pretreatment, with an average increase of 42%. For both LH and testosterone, the changes were time dependent—a greater increase was observed on day 12 compared to day 6 of treatment. Therefore, it is possible that continued treatment with the supplement may have resulted in a further increase in these variables. Although measurements of muscle size and strength were not included in this study, it is possible that the increase in circulating testosterone may be associated with a measureable increase in these variables. Further work is needed to confirm these effects.
While the above findings are interesting and may prove beneficial to those seeking a natural method of increasing circulating testosterone, it should be noted that DAA has been reported to increase aromatase activity, as measured using boar testes (Lamanna et al., 2007b). At the present time it is unknown what amount of DAA would need to be orally ingested by humans in order to promote this effect. No adverse outcomes were noted in the Topo et al. (2009) investigation. Regardless, as with other testosterone stimulating agents, a cyclic schedule of supplementation of d-pol™ is recommended. If adhering to this recommendation, and when considering the inclusion of vitamin D within d-pol™, it may be wise to cycle “off” during periods of optimal sunlight exposure (when natural vitamin D synthesis would be highest—see text below for additional information pertaining to this).
B-vitamins constitute an entire group of water soluble vitamins, with multiple known biochemical effects within the body—as evidenced by the thousands of scientific reports documenting such effects. B-vitamins have known effects in relation to increasing the rate of metabolism, enhancing immune function, and promoting cell growth and division. Of greatest importance in relation to the use of these vitamins within d-pol™, the B-vitamins have been used in combination with DAA for purposes of elevating circulating testosterone: B9 (folic acid), B6 (pyridoxine), and B12 (cyanocobalamin). Because dietary folic acid is not well metabolized to the active form by some individuals due to a genetic defect within the folate pathway, the naturally occurring form of this vitamin (folate) is included within d-pol™.
Nitrate is an inorganic anion abundant in vegetables (e.g., beets, spinach) and converted within the body to nitrite in the entero-salivary circulation (Duncan et al., 1995). The study of nitrate, nitrite, and bioactive nitrogen oxides including nitric oxide, is of great interest to investigators, due to the multiple biological roles of the nitrate-nitrite-nitric oxide pathway (Lundberg et al., 2009).
A relatively new area of investigation is now focused on the use of nitrate supplementation for purposes of improving exercise performance (Bailey et al., 2009; 2010; Lansley et al., 2010; Larsen et al., 2007; 2010; Vanhatalo et al., 2010). In general, the findings from this work indicate an increase in circulating levels of nitrite following nitrate supplementation (possibly suggesting an increase in circulating nitric oxide), in addition to a lower oxygen cost during exercise. Interestingly, these findings are observed after just a few (e.g., 4-7) days of nitrate supplementation. Such results may translate into lower perceived effort at any given submaximal workload or an increase in the actual amount of work that subjects are able to perform during a given exercise session.
While this area of research remains in its infancy, additional studies inclusive of outcome measures beyond blood nitrite and oxygen cost of exercise are needed to more fully detail the ergogenic benefits of nitrate supplementation. To date, the majority of this work has been performed in the laboratory of Professor Andrew Jones at Exeter University in the UK, using beetroot juice as the delivery vehicle for nitrate. In much of this work, subjects ingest 500mL of beetroot juice (providing approximately 350mg of dietary nitrate— the same dosage provided within d-pol™). Other work has used dietary nitrate directly (e.g., sodium nitrate), with the dosage based on subjects’ body mass.
As stated, findings from these studies indicate an increase in circulating levels of nitrite and a reduction in the oxygen cost during exercise. While most exercise studies have involved aerobic work, one recent investigation has focused on resistance exercise (Bailey et al., 2010). In this study, subjects received beetroot juice for six consecutive days and completed a series of low-intensity and high-intensity "step" exercise tests on the last 3 days of supplementation for the determination of the muscle metabolic (using (31)P-MRS) and pulmonary oxygen uptake (VO 2) responses to exercise. As is typical, on days 4-6, beetroot juice resulted in a significant increase in blood nitrite. During low-intensity exercise, beetroot juice attenuated the reduction in muscle phosphocreatine concentration and the increase in VO2. During high-intensity exercise, beetroot juice reduced VO2 slow components and significantly improved exercise time to exhaustion. Moreover, the total rate of ATP turnover was estimated to be less for both low-intensity and high-intensity exercise. The authors concluded that the reduced oxygen cost of exercise following nitrate supplementation appears to be due to a reduction in the ATP cost of muscle force production. These findings are further supported by a recent investigation noting an improvement in mitochondrial efficiency with nitrate supplementation (Larsen et al., 2011), a finding that is also correlated to the reduction in oxygen cost during exercise. Collectively, these changes appear to allow exercise to be tolerated for a greater period of time—which may translate into more repetitions being performed during a given set of exercise and/or a greater load to be used during each set of exercise. For aerobic exercise bouts, the duration of exercise may be increased following supplementation. These are indeed findings of interest to any exercise enthusiast.
Aside from a performance benefit, nitrate supplementation has been reported to lower blood pressure in humans (Kapil et al., 2010; Vanhatalo et al., 2010; Webb et al., 2008), as discussed recently (Ferreira & Behnke, 2010; Gilchrist et al., 2011). Dietary nitrate has been reported to prevent endothelial dysfunction induced by an acute ischemic insult in the human forearm and to attenuate ex vivo platelet aggregation in response to collagen and ADP (Webb et al., 2008). These effects, coupled with the vasodilatory effects of increased circulating nitrite, seem to be responsible for the blood pressure lowering effect of dietary nitrate. While this may not be of primary importance to many athletes, a reduction in blood pressure should at least be of interest to individuals, in particular those who use bodybuilding drugs known to cause elevations in both resting and stress-induced blood pressure. From a general health point of view, a slight reduction in blood pressure is correlated to a lower risk of cardiovascular disease.
In addition to the above benefits of nitrate supplementation, it has been noted that nitrate may also improve the absorption of certain nutrients. While this appears of some interest, because such findings are isolated to designs not involving oral ingestion of nitrate by human subjects, the potential for improved absorption of nutrients following nitrate ingestion it is not a major consideration for the inclusion of nitrate within d-pol™. If such effects on enhanced nutrient absorption are apparent with nitrate ingestion, this would simply be an adjunct to the well-documented performance and health benefits that are observed.
Finally, it is important to address the potential safety concern over ingestion of dietary nitrate, which has been raised (Derave & Taes, 2009; Petróczi & Naughton, 2010), with more specific concern over ingestion of high amounts of dietary nitr ite (Lundberg et al., 2011). This has been appeased in recent years by experts working specifically in this area of research (Benjamin et al., 2009; Gilchrist et al., 2010). The general consensus is that ingestion of low amounts of dietary nitrate appears safe and may be associated with improvements in parameters of health (e.g., vascular function) and physical performance.
Vitamin D is a fat-soluble vitamin with multiple known functions within the body (Holick, 2004; Sutton & MacDonald, 2003; Thacher & Clarke, 2011), ranging from the maintenance of normal calcium metabolism to a modulator of cellular immunity. Vitamin D3 (cholecalciferol) can be synthesized by humans in the skin upon exposure to ultraviolet-B radiation from sunlight. Vitamin D can also be obtained from the diet. Unfortunately, vitamin D is found naturally in very few foods. According to the Linus Pauling Institute, “foods containing vitamin D include some fatty fish (mackerel, salmon, sardines), fish liver oils, and eggs from hens that have been fed vitamin D. In the U.S., milk and infant formula are fortified with vitamin D so that they contain 400 IU (10 mcg) per quart. However, other dairy products, such as cheese and yogurt, are not always fortified with vitamin D. Some cereals and breads are also fortified with vitamin D. Recently, orange juice fortified with vitamin D has been made available in the U.S.”
Based on the above, vitamin D supplementation is likely required by most individuals. This is particular true if exposure to natural sunlight is limited and/or the use of sunscreen in routine. In fact, it has been reported that the majority (87%) of adults living in the relatively sunny climate of Tennessee are deficient in vitamin D (Long et al., 2011); a finding that is well supported by numerous investigations including adults (Holick, 2007), in addition to those including children. Individuals residing in parts of the country where the amount and intensity of sunlight is less than average may be at even greater risk for deficiency. Without adequate dietary intake and/or natural synthesis of vitamin D, multiple components of physical health may be compromised—again, a well documented outcome that has fueled the continued growth of vitamin D research.
Activated vitamin D (calcitriol) has been referred to as a pluripotent pleiotropic secosteroid hormone (Cannell et al., 2009). As a steroid hormone regulating more than 1000 vitamin D-responsive human genes, vitamin D may influence athletic performance. Most of the studies supporting the role of vitamin D with regards to exercise performance involved older adults. However, as noted by Cannell and colleagues (2009) in a recent review article on the topic “physical and athletic performance is seasonal; it peaks when 25-hydroxy-vitamin D levels peak, declines as they decline, and reaches its nadir when 25-hydroxy-vitamin D levels are at their lowest.” These findings are underscored by the potential impact that vitamin D has on skeletal muscle, as described recently (Bartoszewska et al., 2010; Ceglia, 2009; Hamilton, 2010). Furthermore, a recent study (Pilz et al., 2011) in healthy men who supplemented with 3332 IU of vitamin D daily for one year, noted a significant increase in total, bioactive, and free testosterone levels. Although this finding requires confirmation through further research, it appears as though some of the noted health-related effects of vitamin D supplementation in men may be mediated through an increase in testosterone. Considering the well-described health effects of vitamin D, coupled with the potential impact of vitamin D on exercise performance, supplementation with this powerful vitamin should be considered by all individuals.
Research indicates that vitamin D toxicity is very unlikely in healthy individuals when used at amounts less than 10,000 IU/day (Vieth, 1999). However, the Food and Nutrition Board of the Institute of Medicine (IOM) and a recent Clinical Practice Guideline from the IOM in conjunction with the Endocrine Society (Holick et al., 2011) has set a conservative tolerable upper intake level of 4,000 IU/day (100 mcg/day) for all adults. This is similar to the dosage used in many clinical trials and is the dosage provided within d-pol™.
Cofactors for Vitamin D
For optimal vitamin D absorption, taking vitamin D with the largest meal of the day seems most appropriate (Mulligan & Licata, 2010). Beyond this, it has been suggested that certain vitamin and mineral cofactors are potentially needed for optimal vitamin D action and effect. However, it should be noted that the need for these cofactors is debatable. Moreover, most of these co-factors are present in vitamin/mineral supplements, which most individuals consume regularly. The cofactors of interest include magnesium, zinc, vitamin K2, vitamin A, and boron. With regards to boron, aside from acting as a cofactor for vitamin D, one recent report indicates a testosterone elevating effect of this mineral (Naghii et al., 2010). It is possible that this may enhance the action of DAA on circulating testosterone. However, an earlier report for boron refutes these findings (Green and Ferrando, 1994). Collectively considering the above, boron and other co-factors are not included within d-pol™.
Serving Size: 3 tablets
|Amount Per Serving||% Daily Value|
Vitamin D3 (Cholecalciferol)
|Vitamin B6 (Pyridoxine)||2mg||100%|
|Vitamin B9 (Folate)||400mcg||100%|
|Vitamin B12 (Cyanocobalamin)||6mcg||100%|
|LH/Free Testosterone/ATP Amplifying Vasodilatory Oxygen Sparing Matrix||3.6g||**|
|Nitratine (high molecular-yield nitrate form) (std. for 73% nitrates)||480mg|
|Vitamin D3 (Cholecalciferol)||4,000IU|
|** Percent Daily Value Not Established|
% Daily Value based on 2,000 calorie diet
Other Ingredients: silicified microcrystalline cellulose, stearic acid, methylcellulose, silica, magnesium stearate, mannitol
• Take 1 serving with a mixed food meal 60 minutes prior to intense exercise, preferably with a multivitamin/multimineral, which may aid in vitamin D absorption.
• For optimal results, use in conjunction with Muscle Marinade to aid in nutrient delivery and uptake.
• Avoid taking immediately prior to bedtime as your body's natural growth hormone release is at is peak.
• Tolerance to dosing should be assessed by all individuals prior to starting the full dosage of 3 tablets per day.
D-Pol is intended only for healthy adults above the age of 18. Do not use if you are currently pregnant or nursing, could be pregnant, or are attempting to become pregnant. All individuals should consult a licensed healthcare practitioner before using this product. Do not use this product if you have been diagnosed with or have a family history of (including, but not limited to): heart disease, thyroid disease, liver disease, cancer, Barrett's Esophagus, gastroesophageal reflux, diabetes, hypoglycemia, hypo/hypertension, asthma, any psychiatric condition including depression or seizure disorder, or if you are using any other dietary supplement, prescription drug, or over-the-counter drug intended to promote vasodilation, in particular those intended for erectile dysfunction.
The combined use of vasodilatory supplements or drugs and D-Pol could cause an unsafe drop in blood pressure. Discontinue use and contact a medical doctor immediately if you experience an irregular or rapid heart beat, chest pain, shortness of breath, dizziness, lightheadedness, fainting or presyncope, tremors, headache, nausea, or other similar symptoms.
- GREAT!Review by Jimsonskin (20 February 2016)
- PriceEffectivenessTasteit was. ummm GREAT!
- WorksReview by Jake (23 July 2015)
- TastePriceEffectivenessLook I do not know if this increases test levels but I assure you that this stacked with condense turns you into the incredible hulk. I was even scared as to what it did to my strength and state of mind. However without taking this before gym strength was normal. Give it a go. Of course you need to eat sleep and train smart.
- Not worth it in my opinionReview by Shane (21 July 2015)
- EffectivenessTastePriceI bought a bottle of D-Pol pills to see if I'd experience any significant lean mass gains with it. The day before I started the course I went and had a blood test for my testosterone level. Results went to my doctor who was also curious to see whether this stuff did what it says on the bottle. On the last or second to last day of the course (after a month of use) I went for a second blood test for my testosterone level. Results again went to my doctor. The 1st blood test showed a testosterone level of 23 (I don't know what units it's measured in) and the second showed a level of 25. My doc noted that my first test was done in the afternoon/early evening and my second test in the morning. He said it was a very marginal increase and could probably be explained by the natural cycling of test production in the body, going at full tilt in the mornings and slacking off in the afternoons/evenings. That's my two cents' worth. I just thought I'd do it scientifically to see if this stuff actually had any benefits and if it was worth R500 a month. I have concluded that it doesn't and that it's not.
- Works hands down. (used as a gainer and pump)Review by T (14 October 2014)
- TastePriceEffectivenessPersonally I did not experience the great sensation of Libido or a surge in focus but prior to using this product I fluctuated between 74kg and 76kg. After 2 weeks of use I weighed between 78kg an 80kg. Bear in mind I have not been eating well. So this backed by a high calorie diet should show better results.
- Great productReview by derek (15 September 2013)
- TastePriceEffectivenessGreat product for the price and good brand,great results for working out
- Very HappyReview by Renzo (3 June 2013)
- Its not often that a testosterone boosting supplement lives up to its name. But this product proved me wrong and definitely did everything it said it would with great pumps, strength gains and test levels
- Excellent ProductReview by LUELE (19 May 2013)
- Love this stuff! Awesome pumps
- Awesome ProductReview by Jaques (10 February 2013)
- Used this for 4 weeks along with Animal Stak and it was insane to say the least! Taste: I gave a 5 because it's pills so its irrelevant. Price: I gave it a 5 because I could not find this cheaper elsewhere. Effectiveness: Gave this a 4. I got really great pumps from the nitrates, couldn't really tell if I had that much of a test boost, only blood work will really tell. I did have some extra strength though and felt really good and healthy from all the vitamin D. Very good ingredient profile. I would suggest D-pol with Animal Stak for awesome results.
- great stuff!Review by D-bomb (7 September 2012)
- very good product, definitely noticed the increase in testosterone, weights,libido,aggression all felt higher than normal, increase in veins from the nitrates..has helped me maintain a lot of strength while leaning out.
- Buy now!Review by jp (27 June 2012)
- This on its own is a good product. But this stacked with a testo booster like SPS test RX is insane!!!! my strength and endurance has increased and I've weirdly experienced fat loss. Pills are kinda big though.
- Two in oneReview by Johan (19 January 2012)
- I bought this product due to the fact that i needed a natural test booster and after reading up i found that the newest thing is D aspartic acid and by taking 3000mg a day within 10 days testosterone can boost up to 40 percent and this was proven clinically. Then i noticed it also has a No booster which means its a two in one which is great value for money. I haven't noticed an increase in test but to really know i will have to go for a test, as for the no pump that definitely works as im feeling hard in the gym when the blood starts pumping and also veins start showing which wasn't there before. This two in one works well for me so far and im going to use this for two cycles and see what the results will be like.