It is known that many medications have side effects or results other than the intended effect. While usually specific side effects can be linked to the medicine there is a good chance a side effect experienced may not be related to the medicine at all.
This can be referred to as the Placebo Effect which basically means the medication did not cause a change, but in your mind, you think that it did so it seems like it did cause a change. This is something that can easily happen when taking a new medicine or supplement.
Recently I was doing some research and thought about trying out a supplement. I didn't get around to trying it yet, but throughout the day and following day I experienced what would be considered side effects such as headache and irritability. I thought to myself, if I had taken the supplement, I would have definitely blamed these effects on the supplement.
So in this case, these unrelated effects would have been blamed on the supplement incorrectly. This is something to keep in mind because it can happen when taking anything new from a medicine or supplement to even trying a new food.