Ephedrine and guaifenesin are supplements that have experienced increased use over the past decade. Ephedrine, for insatance, has been used as a stimulant and weight-loss product, and guaifenesin as an expectorant and cough suppressant. Plus, both of them are also found in combination in many antitussives and expectorants. Naturally, all drugs may cause side effects. However, many people have no side effects or only have minor side effects. So, you should not hesitate to call your doctor or to get medical help if any of the following side effects bother you or take a long time to go away: trouble sleeping, shakiness and feeling nervous. It is worth noting that Ephedrine and guaifenesin have been shown to cause nephrolithiasis in cases of abuse when taken individually or in combination. Therefore, you must follow the doctor’s instructions if you want to get better. When used during the first trimester in the presence of a febrile illness, guaifenesin has been associated with an increased risk of neural tube defects. It is, however, unclear whether this increased risk derives from the medication use, the illness, or both. So, it’s preferable that you consult your doctor before using this medication.