Valerian is a herbal supplement known for its sedative properties, but there are some potential concerns about its effects on fertility. Studies have suggested that valerian may reduce sperm motility and viability in men, as well as disrupt ovulation in women. It's important to keep in mind, however, that the research on this topic is limited and more studies need to be done before any firm conclusions can be drawn. Additionally, valerian should not be taken without consulting with your doctor first since it can interact with certain medications and cause side effects such as dizziness and headaches. Ultimately, if you're looking to get pregnant or increase your chances of conception then it would likely be best to avoid using valerian until further research has been conducted.