I called it a subscription to a feeling. It turned out I'd run the test wrong.

I thought it was hooey. I want to be accurate about how I said it, though, because I know how I sounded.

What I actually said, more than once, was that it was ground-up cow skin with a nice label on it. My sister-in-law Ashley brought it up at Thanksgiving and I said, out loud, in front of her kids: Ashley, you're drinking gelatin.

That wasn't kind. She has reminded me of it since.

And I want to be exact about what I believed, because it isn't the shape people assume. I didn't think it was a con. I thought the people selling it knew perfectly well it did nothing, and had found a legal way to say so.

Those are different accusations. Mine was the ruder one.

I used that line for a year and a half. Mark(my husband) laughed the first time, and after that I kept using it, the way you do when you realise it actually works.

Then we moved my mother into her care home.

I'd packed her photo albums into a banker's box and I carried it in from the car. It's forty feet of flat sidewalk. Maybe fifty.

I put it down twice.

A kid who works there, twenty or so, came out and took it off me. He didn't ask. That's the part. He didn't say can I get that for you. He just took it, the way you take something off someone who shouldn't be carrying it.

My mother was in the chair by the door watching all of this. She's eighty-one. She said: let him, honey.

She said it in the voice she used when I was pregnant with Cole.

It wasn't a photograph and it wasn't my face. It was that two people decided independently that I'm the one who gets helped now. One of them was my mother.

And I couldn't argue with either of them.

I looked things up constantly. Almost always after ten at night, which tells you something.

Reddit, mostly. The menopause boards. I'd never opened Reddit in my life until all this started. I now know more about my own endocrine system than the physician's assistant who told me my bloodwork was normal and asked whether I'd considered that I might be stressed.

Here's the part nobody had put in front of me. Estrogen helps regulate collagen production in skin and connective tissue, and it falls during the menopause transition.⁶

One reason, not four. Somebody should have sat me down at forty and said so. Instead I found it on a message board at eleven at night, from a stranger, about eighteen months after I needed it.

I have dates because I put them in my phone. I'd like to say that was rigour. It wasn't. I'd decided in advance that I would quit again at week nine, and I wanted to catch myself doing it.

I started, and I wrote the date down.

Nails first, and fast. There's a note in my phone from about few days in that just says: nails ???

By week three there were no question marks. I'd had to start cutting them again, which I hadn't had to do in years.

That's what bought them the next two months. I had something to point at while the rest of it hadn't happened yet.

Hair, somewhere around week two. I noticed it in the drain, which is a grim way to measure anything and the most honest measurement I've got. There was less of it.

Skin I want to be careful about, because I know I wanted this one. Around week four my face felt different in the mornings. Less like it needed something immediately. I don't fully trust that, because I'd been waiting for it since the day I started. If you ask me to point at what changed, I can't. The only fact I can give you is that I stopped using the heavy cream around week twelve and never went back to it.

The joints are the one I'd put in the article.

We have a staircase in this house that had announced me for years. Every riser, the same knee. Mark used to know what floor I was on.

Week five or six, I came down them and they were quiet. I stopped on the bottom step. Then I went back up and came down again, to check.

I did that twice. Half six in the morning, going up and down my own stairs like an idiot. That's the moment I stopped treating this as something I was trying.

If you're standing where I was a year ago, I'd say three things.

The first is that it wasn't your fault. There's a reason your skin and your hair and your knees all shifted inside the same few months, and it isn't that you let yourself go. Nobody sat me down at forty and explained any of it, and I'd want you angry at the right thing. I spent two years angry at myself, and that cost me a lot more than a tub.

The second is about the test. You didn't find out that collagen doesn't work. You found out that a few weeks at a low dose doesn't work, and you've been living off the wrong finding ever since. Nobody gave you the conditions, so you made some up, and then you believed your own bad experiment for a year and a half.

The third is small, and it's the one I'd actually lead with. Don't check the mirror. You'll cheat. We all cheat. You'll stand at a certain angle in a certain light and talk yourself into something or out of it, and either way you'll have learned nothing.

Check the stairs. Check the jar lid. Check whether you're still cutting your nails three months from now.