Why We Started with Projections Instead of Prescriptions

When we started building myTSH, one of the first questions we asked ourselves was simple but important:

Should this tool ever tell someone what dose to take?

The short answer is no. Here's why.

The temptation

It's easy to imagine a "smart" thyroid app that says:

"Based on your last three labs, we recommend increasing your dose by 12.5 µg."

That kind of direct recommendation feels helpful. It also feels dangerous.

Levothyroxine dosing is highly individual. Two people with the same weight, the same lab results, and even the same history can respond differently because of absorption issues, other medications, timing of labs, stress, illness, and a dozen other variables we can't see.

Any system that confidently tells someone "take this amount" is pretending it has information it doesn't have.

What we chose instead

We decided to build a tool that answers a narrower, more honest question:

"If the pattern in your data continues, where is your TSH likely to go?"

This is a projection. It's a forecast. It is explicitly not a prescription.

When you use myTSH, you enter your own data. You choose what "what if" questions to ask. You see the range of possible outcomes, including the uncertainty. Then you take that information to your doctor.

The responsibility stays where it belongs.

This is not a limitation. It's the point.

Some people hear this and think we're being overly cautious or that we're leaving value on the table.

We see it differently.

By refusing to play doctor, we can actually be more useful in the long run. We can focus on making the forecasts as clear and well-calibrated as possible, without the pressure to turn them into recommendations. We can stay on the side of the patient and the clinician rather than inserting ourselves between them.

This philosophy is why the disclaimers on this site and in the app are written the way they are. It's not legal theater. It's the actual operating principle.

If you're looking for an app that will manage your thyroid for you, myTSH is not that app — and it never will be.

If you're looking for a clear, private, low-friction way to see what your own data suggests about where things are headed, then we might be able to help.

That's the line we chose to draw. We think it's the right one.