Yes, you can: the longer you use them, the better you feel. All of our herbs are safe to use based on the recommended dosage. The longer you take them the more beneficial they are. Most of them are unlikely to cause any side effects, but be sensible - for example, Guarana is a great supplement to keep you focus and alerted, providing heaps of energy - but as you would expect, too high a dosage can cause insomnia, stomach irritation, nausea, and increased heart rate. Our herbs can be taken every day and long term. Positive effects are achieved through regular use, even in lower dosages.