“The side effects are just nausea and flushing.”

Not established

The reviewed evidence does not establish this statement. This does not prove it can never be true.

Nausea is the dominant effect in the trial record, severe in 12.9 per cent of subjects at the higher dose in the 2000 study. But the published case literature also contains rhabdomyolysis and renal impairment requiring intensive care, renal infarction affecting roughly half a kidney, and acute ischaemic priapism that failed drug and irrigation treatment and required surgical decompression, a time-critical emergency carrying permanent erectile-dysfunction risk. These are case reports: they prove occurrence, not frequency. The honest statement is that the frequency of serious harm is unknown because no surveillance system exists, not that serious harm is rare.

What this answer is based on

This answer uses observations or reports from people. They can show what happened, but may not prove the substance caused it.

Limits of this answer

The completeness of the adverse-effect picture. Case reports establish that these events happened after use with temporal association; they cannot establish incidence or causation. These limits show which substance, product, people, use, place, and time the answer covers. A different product or situation can have a different answer.

Topic

What is known and not known about harm, warnings, and safety limits.