L-Dopa: Growth hormone releaser
If L-dopa were useful only as a PD treatment, it would be of little interest to most people. Yet L-dopa has uses beyond PD. It has been known for over 30 years that it is an effective stimulant of human growth hormone (HGH) release. In 1970, Boyd and colleagues found that a 500mg oral dose …"caused a significant rise in plasma growth hormone in PD patients, initially starting therapy or on chronic L-dopa therapy for as long as 11 months. The rise in plasma growth hormone persisted for 120 minutes after the administration of the drug." (4). Boden and his co-workers gave 500mg of the drug orally to four male and five female volunteers. "HGH levels rose sharply at 45 minutes from the basal value of 0.8mg/ml, to a maximum of 10.0mg/ml at 90 minutes (p<0.001) and declined thereafter. This rise occurred in eight of the nine subjects." (5). Hayek and Crawford reported that six out of seven "constitutionally short children" responded to oral L-dopa (200-500mg), "…with elevations in HGH concentration above 7mg/ml, peak levels occurring between 30 and 120 minutes after drug administration..". (6).
In 1975, Ajlouni and colleagues reported the effects of 500mg of oral L-dopa on eight normal and 8 non-obese insulin-dependent diabetic subjects. The normal subjects increased their plasma HGH from 1.5mg/ml before L-dopa, to an average 21mg/ml at 90 minutes post L-dopa, with all subjects showing at least a 10 mg/ml increase. The diabetics increased from 2.5mg/ml to 20mg/ml from 60-90 minutes post L-dopa. Giving 100 grams (3 _ ounces) of glucose with, or 30 minutes after the drug totally suppressed the expected HGH increase (7).
Obesity has been shown to blunt HGH release after oral L-dopa. Laurian and his co-workers tested 17 obese, non-diabetic and six normal weight volunteers. All 17 obese subjects failed to respond to L-dopa, while the normal weight subjects had HGH increases of 10-11mg/ml at 90 and 120 minutes after the drug was administered. The 17 obese men and women subsequently lost 12-50kg. After weight loss, 8 people secreted HGH in response to L-dopa, but at levels only 50-60% of the normal weight people. 9 formerly obese people still failed to respond to it (8).
Barbarino and colleagues gave 500mg orally to 12 obese people, with no significant HGH increases. When some of the subjects were given 40mg oral Propranolol, two hours before L-dopa, they then showed HGH response, although at only 50-75% of the level shown by 12 normal weight subjects given L-dopa, whose serum HGH levels reached 7 to 32mg/ml 60-120 minutes after L-dopa (9).
Greenspan et al. compared HGH response to L-dopa in 44 young patients (31-44 years of age) and 42 older patients (64-88 years of age). All were considered "healthy participants". Plasma HGH increased by 221% in the young patients and 167% in the older patients. The post L-dopa HGH levels were similar in young and old (4.5 and 4.8mg/ml) (10).
The preceding studies illustrate some of the studies showing that 500mg oral L-dopa is an effective stimulator of HGH release. Whether a person is male or female, young or old, diabetic or not, thin or obese (possibly with Propranolol), a PD patient or not, L-dopa is a natural HGH-releasing agent when taken on an empty stomach. For those who can't afford HGH injections, or just don't like self-injecting,L-dopa may provide a reasonable alternative.
Dit is een samenvatting van zon beetje alle studies, oh ja en wat ze ook vergeten te vertellen is dat de verhoging slecht 30-120 min in je bloed blijft. En waar ze de testosteron verhoging vandaan halen is me een raadsel.