"Half a tablet is a fair compromise"

The quiet reduction is the quiet stop's more thoughtful cousin. You didn't stop. You cut the dose, or you take it every other day, because the full dose felt like too much and stopping felt like too little, and halfway seemed sensible. The prescriber doesn't know.

The problem is what that does to everything the prescriber does next. Levothyroxine is the clearest case. The dose is set by blood tests, the NHS says, and adjusted until the level is right. If you're taking half, the test comes back low, and the prescriber raises the dose, and now you're prescribed more than you need and taking half of that, and the next test is being read against a dose you're not on. Blood pressure works the same way. The GP sees a reading that hasn't come down on the tablet, and adds a second tablet, when the first one was never really being taken. The quiet reduction doesn't just hide from the prescriber. It feeds them a wrong number and they act on it.

Some of that hiding isn't even deliberate. Research on self-reported adherence finds that people tend to overestimate how well they're taking their medicines when asked, and that self-report is good at confirming that someone is taking it and poor at catching that they aren't. So when the nurse asks "and you're taking the tablets alright" and you say yes, you're doing what most people do, and the record stays clean, and the treatment gets adjusted around a patient who doesn't exist.

None of this means half a tablet is never the right dose. It often is. Antidepressant tapers go down in steps, blood pressure tablets come in several strengths, and a prescriber who hears "the full dose makes me dizzy" will frequently say let's try half. The compromise is fine. Making it in secret is the part that breaks the system. Say "I've been taking half" and you've told the truth to the one person for whom it changes the plan.