Grapefruit juice contains chemicals that can cause problems with enzymes that break down certain types of medicines in your intestines. When a medicine does not get broken down properly in the intestines, you can have too much medicine in your blood. Having too much medicine in your blood increases your chances of having side effects. Medications with a very short half life have the opposite effect not allowing them to work properly or at all. Some affected drugs of certain to us are AI 's as grapefruit juice will increase the effect,causing increased estrogen retention and increased drug retention. As far as as goes, it can help those with poor bioabailability. Here are a couple of very good reads on grapefruit juice and caffeine increasing orals effectiveness
If I may add as well...
Grapefruit extract or juice also has a this pronounced effect with medications and YES including steroids!
Grapefruit juice will increase the potency of most oral drugs including steroids here is the article and a blind study
Study-
Ceska Gynekol. 2003 Mar;68(2):117-21.
[Does grapefruit juice increase the bioavailability of orally administered sex steroids?].
[Article in Czech]
Fingerov? H, Oborn? I, Petrov? P, Bud?kov? M, Jezd?nsk? J.
Source
Klinika porodnictv? a gynekologie LF UP v Olomouci.
Abstract
OBJECTIVE:
To verify if and to which extent the interaction with grapefruit juice can increase bioavailability of orally administered sexual steroids.
DESIGN:
Pilot pharmacokinetics study.
SETTING:
Department of Obstetrics and Gynecology and Institute of Pharmacology, Medical Faculty, Palack? University, Olomouc; Department of Nuclear Medicine, University Hospital, Olomouc.
METHODS:
2 mg of estradiol valerate and 100 mg of micronized progesterone were given to eight healthy postmenopausal volunteers. Blood samples were collected at time 0, 2, 3, 5 and 24 hours after tablets application. The same trial was repeated a week later but tablets were swallowed with 200 ml of grapefruit juice. Serum levels of estradiol and progesterone were measured by RIA. Results were statistically evaluated using the Wilcoxon's nonparametric paired test.
RESULTS:
Though grapefruit juice on average slightly increased serum levels of estradiol (E2) and progesterone, this increase reached statistical significance only for the E2 level 24 hours after application of tablets. The mean area under curve (AUC) of estradiol rose significantly to 117%. The even greater increase in the mean AUC of progesterone (to 125%) was not statistically significant because of marked individual variability of response.
CONCLUSIONS:
Our results suggest that grapefruit juice may increase bioavailability of orally administered estradiol and progesterone. The response varies markedly between individuals. This observation may be of some importance also for users of OC and HRT.
PMID: 12749182 [PubMed - indexed for MEDLINE]
According to the study caffeine is reported to accelerate absorption of some drugs. Our data show that caffeine alters the excretion profile of oxandrolone. With 300 mg of caffeine, there were very large increases (about 20 times) in the amount and rate of excretion for both oxandrolone and epioxandrolone
The Portuguese, who are linked to the doping Laborat?rio the analises the Dopagem , had heard from police that some Portuguese steroids users swore by a combination of caffeine and oxandrolone. The researchers wondered what the point of that combination could be, and dived into the library.
There they came across studies that say that can improve. Caffeine absorption and action of paracetamol [J Clin Pharmacol. 2007 Jun; 47 (6) :715-26]. Would that caffeine also with oxandrolone?
The researchers answered that question with an experiment in which they gave a subject with normal caffeine consumption of three cups of espresso a day a tiny amount of 0.4 mg oxandrolone.
The researchers then looked at how much caffeine for 40 hours, oxandrolone oxandrolone and the inactive metabolite epioxandrolone [structural formula shown here] there appeared in the urine of the subject. The figure below shows only what happened during the first 14 hours. Click on it for the full figure.
Next, the researchers repeated the experiment, but gave the subject there when 300 mg of caffeine in pill form at. You can see in the figure [click for full figure] that the amount of oxandrolone and epioxandrolone fold, respectively 20 and 15 increased by caffeine above.
The researchers suspect that their experiment shows that caffeine intake of oxandrolone greatly improves the body. " Practically this Means That similar Concentrations / Effects May Be Achieved using lower dosages , "they write. " Other anabolic steroids shouldering usefull be Investigated . "
Source: Laborat?rio the analises the Dopagem, IDP, Lisboa, Portugal. B. Salema, J. Ruivo, X. de la Torre, M. Sekera, L. Horta. Oxandrolone excretion: effect of caffeine dosing. Published
ADoP - Autoridade Antidopagem de Portugal.
