can l carnitine cause high blood pressure Role of L-carnitine in Cardiovascular Health: Literature Review Potential Adverse Effects of L-Carnitine

Use immediately after reconstitution as potency degrades rapidly

This work was supported by grants from the OIST (to M.Y.), from the Ministry of Education, Culture, Sports, Science, and Technology of Japan, and from the Japan Science and Technology Agency (to H.K.)

International Urogynecology Journal

While protocols vary widely, a common range for animal studies falls between 1-10 mcg per kg of body weight

However, much of the research has illustrated that such an effect is a negation of caffeines ability to raise blood pressure rather than an ability of L-theanine to take a persons blood pressure down below its normal resting state.26 Also, in some research looking at L-theanine in isolation (or, more specifically, in mango sorbet), no effect on blood pressure was observed.27 It appears that L-theanine should be mostly safe for most people, but its always a good idea to talk to your doctor before introducing any new supplement into your regimen