Vidalista 2.5 mg (tadalafil) could potentially affect sleep, but sleep problems/insomnia aren't among its most common side effects. Tadalafil more commonly causes headache, indigestion, flushing, nasal congestion, back pain, muscle aches, or dizziness. If you notice difficulty sleeping after taking it, possible reasons include headache, nasal congestion, or individual sensitivity to the medicine. If you're taking 2.5 mg daily and the sleep problem started after beginning tadalafil, consider discussing the timing and symptoms with your doctor or pharmacist. Don't increase or change the dose on your own. If you tell me what time you take Vidalista 2.5 mg and what kind of sleep problem you're having, I can help you assess whether the timing could be contributing.