Looking back through my records, my HDL was below 40 at 6 months. A year later, it was near 50. Hit the mid 50s about 2.5 years after starting. It’s in the mid 50s now, though I haven’t had a test for over two years. (Getting one this week.) On my 10th year of keto.
Only got tests done infrequently, though, so it’s hard to gauge when things occurred.