Do the ingredients in preworkout or thermogenics make birth control less effective? I was wondering about the pre-workout supplement called Epiq Rush from GNC? If you could let me know I would greatly appreciate it.
I can certainly give you the best information I can! I always preface these type of questions by saying that it is sometimes difficult to give exact answers when looking for interactions between medications and vitamin/supplements. This is because vitamins/supplements, such as Epiq Rush, aren't tested for drug interactions like prescription drugs are. Having said that, there typically is some decent information available so I will share what I have.
First we need to look at the ingredients for each of the supplement that you mentioned, Epiq Rush pre-workout supplement:
Epiq Rush Ingredients
Let's look at all of these ingredients separately:
Aspartic acid is an acidic amino acid, used by humans as a building block for protein synthesis. Aspartates are used orally to increase absorption of mineral supplements, to reduce fatigue, and to enhance athletic performance. There are no known interactions with aspartic acid and oral contraceptives.
Taurine is a constituent of some energy drinks, including Red Bull®. Numerous clinical trials suggest Red Bull® and similar energy drinks may be effective in reducing fatigue and improving mood and endurance. There are no known interactions with taurine and oral contraceptives.
L-citrulline is converted to L-arginine, L-citrulline may have pharmacological effects similar to L-arginine. L-citrulline is also used for stimulating immune function, body building, increasing energy, and improving athletic performance. The nitrate portion of citrulline is used to gain "pumps" or increased blood flow to aid in a workout. There are no known interactions with citrulline and oral contraceptives.
Cordyceps sinensis extract
This is actually a type of fungus, also known as Ophiocordyceps sinensis. It is used for and thought to enhance athletic performance. There are no known interactions with this and oral contraceptives.
Epiq Rush Blend Portion
Everything in this section, aside from the raspberry ketones, are components of coffee or green tea and have caffeine like effects. Caffeine has fairly obvious effects that we are all familiar with. The raspberry ketones have high levels of antioxidants and are thought to possibly aid athletic performance. There really isn't any interaction here either as normal amounts of caffeine are typically fine in patients on contraceptives. Studies have shown that estrogen compounds such as estradiol (which is common in most birth controls) may reduce how quickly caffeine is eliminated from the body (Study link: http://www.ncbi.nlm.nih.gov/pubmed/7359014?dopt=Abstract) . Nothing major here though.
The last two ingredients also came up with nothing in terms of interactions. Based on all the available evidence, I can't see any interaction between oral contraceptives and Epiq Rush.