Sildenafil (Viagra) and similar drugs are among the most counterfeited medicines in the world. Pills from unverified online sellers may contain no active ingredient, too much, or undeclared substances, and are made without quality control. This is a genuine safety hazard, not just a value concern.
The bigger danger is skipping the medical check. These medicines can cause a serious, even life-threatening drop in blood pressure if combined with nitrate heart medicines or certain other drugs, and they are not suitable for everyone with heart disease. A proper assessment exists to catch this.
Use a regulated pharmacy or a legitimate telehealth platform where a clinician reviews your health and medications first. If you have heart problems or take any heart medicine, speak to a doctor before using any erectile dysfunction medication. Seek urgent care for an erection lasting more than four hours, as this is a medical emergency.