Supplement Roundup: D

Here's a brief rundown on all the supplements in the "D" category that are interesting and/or effective.

Remember, I've ranked them from 1-10 with 1 being – don't even bother, 10 being – you MUST use this supplement, and 2 -9 increasing in importance and effectiveness with the number.

D-ASPARTATE

Also known as D-aspartic acid, this amino acid is produced naturally in the pituitary gland where it stimulates the release of luteinizing hormone (LH). LH travels via the bloodstream to the testicles where it causes a boost in testosterone production. D-aspartate is also produced inside the testicles and acts on Leydig cells (special cells in the testicles that produce testosterone) to increase testosterone production as well as the production of sperm. This appears to work by D-asparatate's ability to increase levels of the nucleotide cyclic AMP, which is a messenger that acts to boost testosterone production. A study performed by Italian scientists reported that men taking the D-aspartate for just 12 days increased their testosterone levels by over 40%.

• Take: 3 grams of D-aspartic acid in the morning.
• Rank: 8 – While D-asp is quite effective for boosting testosterone levels, it is not critical for everyone to take.

DAMIANA

This shrub, also known as Turnera diffusa has been used for centuries as a sex booster. However, it wasn't until recently that it was discovered just how Damiana provides its benefits by University of Mississippi researchers. They discovered that Damiana leaf extract inhibited the aromatase enzyme, which converts testosterone into estrogen in the body. They found that the active ingredients in Damiana called pinocembrin and acacetin were mainly responsible for this effect.

• Take: 50-500 mg of Damiana extract 30-60 three times per day between meals
• Rank: 6 – Boosting testosterone levels is not critical for everyone, nor is using an aromatase inhibitor. However, damiana is still fairly effective for those who want to boost testosterone.

DEHYDROEPIANDROSTERONE (DHEA)

Produced by the adrenal glands, the hormone DHEA is involved in several important physiological processes in the body. These include supporting insulin function, increasing bone density, promoting mental health and, of course, working as a precursor for testosterone. Research has found that DHEA helps reduce bodyfat, particularly from the midsection. It also increases levels of insulin-like growth factor-I (IGF-I), an anabolic factor critical for muscle growth. Although DHEA is thought of as an "old man" supplement, levels can start to decline in the early 20s in males who train intensely.  So supplementation can help to add mass and strength as well as drop body fat for males of any age. It's also a good supplement for women to take since DHEA is the main way that women make testoterone. Yes, even women need some testosterone.

• Take: 25-100 mg once or twice daily
• Rank: 9 – I highly recommend DHEA for any one from 25 on up.

DIGESTIVE ENZYMES

Enzymes are proteins that act as catalysts in the body, enabling metabolic processes to occur at lightning speed. They also break down the macronutrients — protein, carbs and fat — we eat. Of course, the ones of most importance to those of us who train and eat a high-protein diet are the protease enzymes that break down protein. Supplementing with these enzymes helps you better digest the protein you take in and therefore enables you to absorb more for enhanced muscle growth. Research also shows that they can also help accelerate muscle recovery after workouts as well as reduce swelling and speed the healing of injuries.

• Take: 250–500 mg of protease enzymes about 15 minutes before meals. Choose an enzyme formula that contains some or all of the following: trypsin, chymotrypsin, pepsin, pancreatic enzymes, bromelain and papain. Many protein powders now include various enzyme mixes, such as Aminogen, which has been shown in research studies to enhance protein absorption.
• Rank: 8 - Digestive enzymes, especially proteases can help with absorption and therefore recovery and growth. I don't think that you necessarily have to go out and buy digestive enzymes to add to your regimen, unless you tend to have digestive issue when you eat meals or down protein shakes, but if your protein powder has enzymes added to it that can be a good bonus.

DIINDOLE/DIINDOLYLMETHANE (DIM)

Diindole is a chemical found in certain vegetables that can help to decrease the amount of "bad" estrogen in the body. This can help to keep testosterone levels higher, increase fat burning, and reduce fluid retention. Cruciferous vegetables, such as broccoli, cauliflower, cabbage, and Brussels sprouts actually contain the phytochemical indole-3-carbinol (I3C), which the body converts into DIM. DIM can also help to reduce the risk of prostate cancer by binding to prostate cells and protecting them. While eating cruciferous vegetables is a good way to get I3C and therefore DIM, you can also take DIM in supplement form.

• Take: 200-300 mg in two or three divided doses. Taking DIM with vitamin E can increase its absorption.
• Rank: 7 – DIM is helpful for reducing the risk of prostate cancer, but its effects on boosting testosterone and therefore muscle growth are not that remarkable.

DIMETHYLAMINOETHANOL (DMAE)

DMAE was originally marketed in the 1960s as a prescription drug to enhance learning and memory in individuals with attention disorders. Research shows that it leads to higher choline levels in the brain, better than taking choline itself. This effect seems to be due to the fact that DMAE inhibits the breakdown of choline, which should lead to higher acetylcholine levels and, thus, better mental function and even muscle strength. Plus choline is involved in the production of betaine, which has been shown to increase muscle strength and power.

• Take: 100-200 mg once or twice a day
• Rank: 8 – DMAE is a potent brain booster.

DIMETHYLAMYLAMINE

This stimulant, also known as methylhexanamine, as well as 1-3-dimethylamylamine, is the active ingredient found in geranium oil. Although it has been compared to caffeine, many claim that its stimulant effect is much different. Anecdotal reports claim that dimethylamylamine provides a euphoric effect that enhances workouts better than caffeine. In addition to increasing alertness, it can enhance mood, decrease hunger, and aid fat burning. It's able to do all this because its chemical structure is similar to the neurohormone norepinephrine. Norepinephrine is related to epinephrine (adrenaline), which ramps you up, boosts your brain function, increases your metabolic rate and enhances your body's ability to burn up fat for fuel. This all leads to more intense workouts with greater strength and endurance.

• Take: 25-50 mg of dimethylamylamine or 150-500 mg of geranium extract about 30 minutes before workouts.
• Rank: 7 – I know that many people out there would give this stimulant a 9 or even a 10. However, personally I would give it a 6 at best. But again that is due to my personal preference. So I bumped it up a bit to a 7 given that many people do love it. I just don't like the kind of jolt it gives. Plus, many guys are reporting cases of what is called "stim dick". It appears to be a stimulant, much like ephedrine, that can cause some temporary impotence.

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