The best time to take Viagra is 30 minutes before sexual activity, and when the timing of sex cannot be predicted, it should be strictly controlled 1-4 hours before sexual activity. Viagra, scientifically known as sildenafil, is a drug used to treat erectile dysfunction, and the best time to take the drug is 30 minutes before sexual activity. But for it to work to improve erectile function, there must be sexual preparation, otherwise there will still be no erection. In another case, there is no way to predict when there will be sexual activity, you can take Viagra 1-4 hours before sexual activity, which can also play a role in improving erectile dysfunction. However, the prerequisite for this is also sexual preparation, otherwise the effect of the drug is ineffective. Because Viagra is a short-acting drug, it needs to be taken strictly 1-4 hours before sexual activity, preferably 30 minutes before. Other drugs for erectile dysfunction, such as tadalafil and vardenafil, have a long half-life and can be taken at any time of the day, and then sexual activity at any time of the day will have a very good effect on improving erectile function. After taking the drug before intercourse, the diet should be careful to avoid alcohol and fatty meals, which may affect the effect of the drug. In addition, a certain amount of sexual stimulation and desire should be maintained while taking the drug.