the question collapses two mechanisms that aren’t the same thing, and the whole “noticeable effect over time” framing rides on that. a constriction ring works by venous occlusion. it traps outflow once you’re already engorged. that’s it. there’s no arterial inflow story and no plausible mechanism for a durable training adaptation from intermittently restricting venous return a few times a week. so “effect over time” is the wrong axis. the acute mechanical effect is real and immediate, a cumulative one would need a pathway nobody has shown. the vibration is a separate thing entirely. the penile vibratory stimulation literature I’ve read (the bulk of it is spinal cord injury / anejaculation work, methods sections, not the consumer-product writeups) is about triggering a reflex arc, not about blood flow. people import that data sideways into a performance claim it never tested. so before anyone reports “it works longitudinally,” the question I’d ask is the measurement one. what’s the outcome, how are you scoring it, at what interval, and what would a null look like to you. a vague better-over-three-weeks with no baseline is expectancy, not signal. you’re measuring something. I’m just not convinced it’s inflow, and definitely not a trend.