However, if you have medications that are considered a controlled substance including some cough medicines, tranquilizers, sleeping pills, antidepressants, or stimulants, you may only bring up to 50 dosage units across the border without a prescription. But the plan addresses imports only at the wholesale level; it is silent about the transactions by millions of Americans who already buy their medications outside the United States. All medications must be declared upon arrival at the border. If you are taking sildenafil to treat PAH, you will probably take sildenafil three times a day with or without food. What special dietary instructions should I follow? Wentzell found that of men well into retirement age the most likely to self report erectile dysfunction were the least likely to consume drugs to fix their problem. That is why Pfizer has chosen the country for the introduction of Viagra Jet, a tablet that can be taken without water and will dissolve quickly — making it more convenient to use in the heat of the moment.According to one report, erectile dysfunction drug sales may increase percent in South America by But experts are unclear about the reasons for the drastic growth. “ . Buying Medication in Mexico or Canada Healthy Aging Feature Stories Healthy Aging Guide From the MD Archives Buying Drugs Across the Border Discount pharmacies line .  · You’ll likely start with a Viagra dose of 50 mg. You’ll typically take Viagra about 1 hour before sex. You can take the drug 30 minutes to 4 hours before you anticipate sexual activity.