In the our many past articles at fitFLEX, we looked at the growing use of insulin by bodybuilders. As explained in previous
articles, injectable insulin can pose serious dangers to those who rely on it for growth. On the other hand, many wise
bodybuilders avoid injectable insulin, and instead use drugs that stimulate insulin production or compounds that have
In this current article, we'll cover bath the drugs and the supplements currently being used by bodybuilders to produce
insulinlike effects without, in most cases, the severe hypoglycemic side effects.
CARBOHYDRATES AND AMINO ACIDS
There are a number of natural compounds that increase the release of insulin. The most obvious are simple and complex
carbohydrates: Sugars and starches both increase insulin release.
High-glycemic foods are absorbed rapidly if they are not ingested along with other foods - especially those containing fats
and protein - which usually results in a more rapid but less sustained insulin release. The rapid absorption of these
high-glycemic foods increases insulin levels dramatically, of course, but with a resulting rapid drop in blood sugar. The
oversupply of insulin relative to the glucose load soon drops blood sugar below normal levels, which produces hypoglycemic
symptoms such as sweating, dizziness, tremors and increased appetite. To compensate, the body mobilizes its defenses,
releasing catecholamines, glucagon and growth hormone to stabilize blood sugar.
Certain amino acids, such as arginine and glutamine, will also increase the release of insulin. The action of these amino
acids may be synergistic with that of carbohydrates, producing an enhanced insulin response when used together.
Bodybuilders can use the insulin response constructively - especially after training. During the one-to-two-hour window after
training, ingesting carbs and amino acids has a dramatic anabolic effect. The enhanced insulin response drives glucose and
amino acids into muscle cells and increases both protein and glycogen synthesis. The increased testosterone and growth hormone
normally found after high-intensity exercise increases protein synthesis even further.
A number of nutritional supplements are being used by bodybuilders to either maximize endogenous insulin production or mimic
the action of insulin.
The most innocuous of these compounds, chromium, has been shown to be essential to carbohydrate and fat metabolism. The need
for chromium increases with exercise,' and because modern refined diets provide little of the compound, there may be a need
for chromium supplementation in some cases. Chromium-deficient diets have also been linked to diabetes and cardiovascular
Whether chromium provides any anabolic effects of importance to the athlete has yet to be proven. My own experience, along
with anecdotal evidence from athletes, suggests that it doesn't. However, because intense exercise may increase the likelihood
of chromium deficiency, I generally prescribe it for athletes as a preventive measure. A decrease of insulin function can
result from chromium deficiency, and this would seem to jeopardize growth and progress for a bodybuilder. Because of its
possible effects on anabolic drive, and the general health problems chromium deficiency can bring, I usually recommend that
athletes take some supplementary chromium.
Another compound used to provide an insulinlike effect is vanadyl sulfate. Vanadyl has been shown to mimic the effects of
insulin on glucose and lipids. Before we get into the possible effects of vanadyl on bodybuilders, we should know a bit more
Vanadate (a salt of vanadic acid, which is a derivative of vanadium) is an essential trace element present in most tissues
in the body. However, we really don't know what effects it has on cellular metabolism. Vanadate and vanadyl sulfate enter
the cell and are subsequently reduced to vanadyl ions once inside.
Numerous studies have attempted to examine vanadium's possible roles as an essential micronutrient, an environmental pollutant
generated by fuel consumption, and an agent affecting various bodily processes. Of interest to bodybuilders, both the vanadate
and vanadyl forms of vanadium - as well as bis(maltolato) oxovanadium(IV), a complex of vanadyl and maltol that has been shown
to be much more potent than vanadyl sulfate - have been proven to elicit several insulinlike effects.
In one recent study, ingesting vanadate produced a marked and sustained improvement of glucose homeostasis in obese, diabetic
and insulin-resistant mice. In this study, vanadate did not appear to increase insulin sensitivity; rather, it produced a
hypoglycemic action by exerting a direct insulinlike effect on liver and peripheral tissues.
It has been shown that vanadate markedly improves glucose homeostasis in streptozotocin-diabetic rats through an insulinlike
mechanism. However, the authors of this study concluded that vanadate does not reproduce the anabolic effects of insulin. The
reason: Despite improvement in their diabetic state, vanadate-treated rats did not gain more weight than untreated rats. On
the contrary, in several studies, vanadate caused a decrease in bodyweight in control group and diabetic rats resulting from
decreased food intake.
Vanadate has also been shown to preserve insulin-stimulated lipogenesis after the removal of insulin. Thus, it appears that
vanadate may prolong an increase in bodyfat beyond the effects of insulin.
Another recent study examined the effects of administering vanadyl orally to diabetic rats. This study produced several
interesting results. It would seem that vanadium, when used in vanadyl form, is effective in diminishing the diabetic state
in the rats by substituting for and replacing insulin, or perhaps by enhancing the effects of endogenous insulin.
The study found that, in the presence of vanadyl, decreases in the rates of growth and circulating levels of insulin were the
only significant alterations recorded in control animals. In contrast, diabetic animals treated with vanadyl had normal plasma
concentrations of glucose, lipids, creatinine and thyroid hormone, despite having lower bodyweights and insulin levels.
Other studies have also found that orally administered vanadate, while effective in diabetic rats, has little effect on plasma-
glucose levels in nondiabetic rats." So what kind of picture forms of vanadium and vanadyl? Not good. While vanadyl sulfate has
been shown to mimic the effects of insulin on glucose and lipids, there is no evidence to date that vanadyl mimics the anabolic
effects of insulin. In fact, there's some evidence that the use of vanadyl can be counterproductive. Overall, its use may lead
to increases in bodyfat and decreases in lean body mass in normal animals.
Besides these negative effects, vanadyl and vanadate can also be toxic. In some studies, high doses of vanadate caused toxic
effects in liver function. The use of vanadyl with other hepatotoxic compounds (such as oral anabolic steroids) may even lead
to cumulative liver toxicity. The bottom line is that the chronic use of vanadium or vanadyl in any form is likely
counterproductive. It may lead to toxicity and, if severely abused, even death.
ORAL INSULOGENIC AGENTS
There are a number of drugs that mimic the effect of insulin, increase natural insulin secretion, or both. These drugs are
routinely used to treat adult-onset diabetes.
The most commonly used drugs are the sulfonylureas. This class of drug includes acetohexamide, chlorpropamide, glipizide, glyburide,
tolazamide and tolbutamide. These drugs act by increasing the production and release of insulin from the pancreas.
These drugs can produce severe hypoglycemia in certain individuals, although not as often as insulin does. Since their main action
is to augment the release of insulin secondary to elevated glucose levels and other physiological stimuli, any hypoglycemia produced
is usually self-limiting. As blood-sugar levels fall, the drugs' effect on insulin release diminishes, thus limiting hypoglycemia.
However, in some cases, hypoglycemia can be prolonged and severe, sometimes requiring hospitalization and ongoing intravenous
Another class of drugs used worldwide - but comparatively seldom in North America - is the biguanides. Both metformin and phenformin
inhibit the formation of sugar by the liver, and they increase the transport of glucose into cells by increasing insulin sensitivity.
Because they do not cause clinical hypoglycemia, they are potentially good oral medications for diabetic agents. Because of its
tendency to cause lactic acidosis, phenformin is not generally available. Metforrnin, however, is available in many countries,
although not as yet in the United States.
Several other compounds are currently being investigated as possible treatments for diabetes. One of these compounds, pioglitazone,
a thiazolidine derivative, lowers glucose and decreases insulin resistance. It inhibits the diabetogenic action of growth hormone,
but not its ability to promote growth.
Other candidates are certain peptides that have glucose-lowering effects, and thus may be useful in treating diabetes. Insulinlike
growth factor 1 (IGF-1) may be especially promising. Its multiple therapeutic actions include inhibiting catabolism, stimulating
anabolism, decreasing triglyceride and cholesterol levels, and dramatically increasing insulin sensitivity. These capabilities make
IGF-1 an interesting candidate for treating diabetes.
Overall, insulogenic drugs, while potentially useful for treating diabetes, are not meant for nondiabetics. Other than potentially
dangerous hypoglycemic effects, their short and long-term effects have not been adequately studied.
Because of the dangers involved with insulogenic compounds, it's best to stay away from them. However, manipulating your endogenous
insulin levels through diet and training is an effective and safe way to maximize insulin's anabolic effects.