original: The most common side effects of taking methylphenidate are nervousness and insomnia.
simplifications: The most common side effect of Ritalin is Nervousness and trouble sleeping. Some side effects of methylphenidate drug are nervousness and sleeplessness. Common side effects of methylphenidate are nervousness and insomnia. The most common side effects of methylphenidate are nervousness and trouble sleeping. Nervousness and insomnia are normal side effects of methylphenidate. Methylphenidate's most common side effects are nervousness and insomnia. Nervousness and insomnia are the most common side effects of methylphenidate. The most common side effects of taking methylphenidate are nervousness and insomnia. The most common side effects of taking methylphenidate are tension and  restlessness. The most popular after effects of taking methylphenidate are nervousness and lack of sleep.