Ginko and Prolactin
- 10-23-2009, 12:22 PM
Ginko and Prolactin
Animal study: ginkgo is prolactin inhibitor (from ergo-log.com)
Ginkgo biloba supplements decrease the production of the testosterone-inhibiting hormone prolactin in the body, according to Taiwanese researchers in Hormones & Behavior. Ginkgo probably increases the dopamine levels in the brain. Dopamine inhibits the release of prolactin.
The Taiwanese tested male rats, which were given ginkgo daily for four weeks. The researchers used four groups of animals, which were administered zero, 10, 50 or 100 mg of ginkgo per kg body weight per day. During the month the researchers put the male rats together with female rats and recorded the number of times they had sex. The figure on the right shows the number of times the rats had sex during the last day of the test.
Because the researchers wanted to know how ginkgo stimulates the sexual behaviour of rats, they measured the testosterone and prolactin levels. The effect was most clear in the group of animals that had received 50 mg per kg body weight a day.
In high concentrations, prolactin inhibits the production of testosterone. But even when prolactin levels are too low to reduce the production of testosterone, prolactin can still reduce the sex drive. When the researchers examined the brains of the rats in the 50 mg group, they discovered higher concentrations of dopamine and its metabolite 3,4-dihydroxyphenylacetic acid. The Taiwanese researchers think that this is why ginkgo acts as a prolactin inhibitor. They also tested whether ginkgo influences the production of testosterone in the testes directly, but the results were inconclusive.
Ginkgo decreases cortisol levels after stress 16.08.2008
Ginkgo protects elderly against first signs of Alzheimer’s 16.08.2008
Horm Behav. 2008 Jan;53(1):225-31.
- 10-23-2009, 04:08 PM
- 10-23-2009, 04:19 PM
dsade reminded me that due to rats increased metabolic rate you must convert rat study dasages by dividing by ~6 to get the proper human dosage. Thus, for me at ~275 lbs. I would require 6 g./day of Ginko based on this study; HOWEVER, you must divide by 6 to get ~ 1 g./day.
Anyway, dsade suggests 1 g./day divided into 3 doses.
10-23-2009, 04:27 PM
10-23-2009, 11:46 PM
do ppl sell ginko powerder, maby usplabs could isolate the active and sellit
10-24-2009, 10:51 AM
hmm, may depend on the strength of the powder, but a gram/day seems like alot. if i remember right the powder i had was pretty potent & just a small amount was substantial.
10-24-2009, 05:11 PM
Most come in 60mg caps. At least the NOW foods, I shouldnt say most. 1g is a lot..
10-24-2009, 05:42 PM
Now also sells 120 mg. caps on Nutraplanet. So, for me weighing ~ 275 lbs. I would need approx. 1 g./day = 9 caps divided into 3 caps 3 x day.
Remember, the study cites 50 mg./Kg. bodyweight as the most effective dose FOR RATS. Again this dose must be divided by 5-6 to account for the much greater metabolic rate of rats.
10-24-2009, 07:46 PM
10-25-2009, 01:17 AM
Sorry guys, you're right. Seth Roberts cleared it up: say you weigh 220 lbs.=100Kg.. You take your weight in Kg.=100 x 10 mg. (1/5 the most effective dosage in the rat studies, in order to adjust for rats having a much greater metabolic rate)= 1000 mg. Now if your extract is a 50:1 extract (which the NOW brand is), a 60 mg. cap of extract is produced from 3 g. of Ginko--much more than the 1 g. you need.
In other words seth was saying that one 60 mg. cap/day should be enough to see prolactin inhibiting effects in anyone.
Pop those caps!
10-25-2009, 01:19 AM
10-25-2009, 03:08 PM
cool stuff. i always kind of liked the ginko, it does seem to boost the blood flow to the brain significantly/noticably. great with your morning stim stack.
10-25-2009, 03:27 PM
Yeah, I'll be adding Ginko to the next cycle where I use any "tren" product. Did you also catch the reference at the end of the study outline about Ginko lowering cortisol; makes sense that Ginko would lower both prolactin and cortisol if the researchers are right and Ginko is a Dopamine agonist.
10-26-2009, 04:42 PM
whats the best source for cheap ginko? can you pick up the ones at rite aid or are those crap? im very interested in controling my prolactin levels any way possible.
10-26-2009, 04:48 PM
10-30-2009, 12:12 PM
To be honest, I don't really seem to have as much of a problem on cycle with "tren" products; but they really kill my libido and shut me down hard after the cycle.
I think I would stick with a known quality brand. Nutra carries the NOW brand. At any rate you want to make sure your Ginko product is a standardized extract of the following potency: 24% Ginkgoflavonglycosides and min. 6% Terpene Lactones. If it does not specifically state these standardized potencies, then do NOT buy it.
10-30-2009, 04:35 PM
Gingko biloba is traditionally a nootropic. It is reknown for increasing concerntration by vasodilation (in the brain). Its one of the few noots that works on almost everyone.
World memory champ. uses it before world record attempts.
Its good to see its good broader spectrum usage. Wonder how it works? I just buy bulk powder and cap. Tastes awful.
10-31-2009, 12:33 AM
As the article states, it appears to be a dopamine agonist.
11-01-2009, 09:09 AM
11-03-2009, 03:05 PM
not everyone is going to respond the same, especially to a non-pharmaceutical; you're a perfect example, if you didn't respond to 240 mg.--if it was a quality standardized extract--you're not likely to benefit from Ginko period (at least not for this application).
P.S. I also advise anyone to use 3-4 x day (180 mg.-240 mg.), due to its short half-life and it's inexpensive and safe at these dosages.
11-14-2009, 03:20 AM
hmmmm i am in AUStralia so we dont have all the fancy stuff. What i do have is
2000mg ginkgo, but it is 10.68mg flavonglycosides and 2.68mg bilobalide per cap...
how many of these to get the 1g magic amount???
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