Does Viagra raise or lower blood pressure? Viagra lowers blood pressure, mildly, as part of how it works. This is usually a small and harmless effect in healthy men, but it is the key reason why Viagra interacts dangerously with certain other medicines and must be used with care in some heart conditions. Understanding this effect explains many of the safety rules around the drug.
Does Viagra raise or lower blood pressure?
Viagra lowers blood pressure mildly as a vasodilator. This is usually harmless in healthy men but is why it must never be combined with nitrates.
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Why Viagra lowers blood pressure
Viagra's active ingredient, sildenafil, is a vasodilator: it relaxes blood vessels to improve blood flow to the penis. Because this vessel-relaxing effect is not entirely confined to one area, it also produces a small, general fall in blood pressure throughout the body. In most healthy men this drop is mild and causes no problems, and it passes as the medicine wears off.
The mild effect in healthy men
For a man without cardiovascular problems, the blood-pressure-lowering effect of a standard dose of Viagra is modest. Occasionally it may cause a brief feeling of light-headedness or dizziness, especially on standing up quickly, but it is generally well tolerated. This is simply the flip side of the medicine's vasodilating action, and not a cause for alarm in itself.
Why it matters: dangerous combinations
The blood-pressure effect becomes important when Viagra is combined with other drugs that also lower blood pressure. The most dangerous of these are nitrates, which together with sildenafil can cause a sudden, severe and potentially life-threatening fall in blood pressure — an absolute contraindication. Caution is also needed with alpha-blockers and with some blood pressure medicines, as covered in whether Viagra can be taken with blood pressure medication.
Using it safely
Because of these effects, Viagra is prescription-only, and a doctor checks your blood pressure, heart health and other medicines before prescribing it. If you have low blood pressure or a heart condition, this assessment is especially important. For related questions, see whether Tylenol can be taken with sildenafil and the difference between 50mg and 100mg Viagra. More guides are in the male potency and erectile dysfunction section.
Frequently asked questions
- Does Viagra raise or lower blood pressure?
- It lowers it mildly, as part of its vasodilating action. In healthy men this is usually small and harmless.
- Is the effect dangerous?
- Not by itself in healthy men, but it becomes dangerous combined with nitrates, and needs care with some other blood-pressure drugs.
- Who should be careful?
- People with low blood pressure or heart conditions, and anyone taking nitrates or alpha-blockers — hence the need for a prescription.