Remember that the body has both good bacteria AND bad bacteria inside it. With our poor diet habits and antibiotic use, it is not uncommon for there to be a less than ideal balance between the good and bad bacteria. When you start introducing beneficial microbes into your system, the bad bacteria start to die off. As the pathogens are being killed off, they release toxins which can cause a multitude of symptoms. These symptoms include but are not limited to: increased stress, mood swings, headaches, general unwell feeling, bloating, digestive distress, rash, and a lack of energy. This typically means the probiotic is working. You can always consider reducing your dose and slowly increasing to the suggested daily dosage on the bottle over a few weeks. As always, contact your physician with any concerns.