LarreaRx has been used to treat herpes for centuries, but it is only recently that modern research has tuned into the anti-herpes effect of LarreaRx. They have found, both from case studies and from laboratory research, that LarreaRx is both safe and effective.f you already have liver problems, you should enlist the help of your health practitioner to monitor your liver function. Otherwise, LarreaRx is safe.