I have seen people thicken their hair prostaglandin protocols but few. But granted some of these protocols require consistency. Money and accurate solutions.
I too have read and seen photos of people who regrew hair using aspirin but it must be said that there is a possibility of bias. Photo lighting deception and even the shampoo they use may falsely provide a cosmetic effect. They may even be suffering from a different form of hairloss and not the classic mpb.
I think classic MPB vs. other forms is a bad way to look at hair loss. Women with serious PCOS or post-menopausal symptoms eventually come to exhibit so called MPB, with temporal recession and crown loss. Many men suffer from diffuse hairloss (that is supposedly not MPB) which in time evolves into more typical MPB, with diffuse characteristics. Ultimately, in all sexes and ages, hair is most often sparse at the temples and the crown first. That is true for babies (who have hair 'loss' which is eerily similar in pattern to MPB), older women, women with reproductive problems (many have temporal hair loss), and of course elderly man.
Where it differs is individual circumstances. It is undeniably true that everybody has less hair when they die than they did when they were children/young teenagers. However, some might have good biological traits and thicker head of hair to start with. This can readily be observed in people who have low hairlines. Their scalp often moves with their eyebrows and they have very full hair, often keeping dark color well into their 80s. I think these people typically have stronger metabolisms at those ages. Other teenagers have wimpy hair to start with, and other young adults experience psychological shock which causes diffuses hair loss and then can't escape from the stress of living and never recover their hair, leading over time to MPB traits and eventually, full vertex baldness.
Women of reproductive age are somewhat protected from the rapid baldness men experience, because even with infrequent menstruation, their ovaries still produce progesterone. And progesterone-derived medications like spironolactone and finasteride are some of the few substances that have truly reversed pattern hair loss. Just like women during healthy pregnancies.
Aspirin is just one aspect of an extensive approach to fix fundamental metabolic problems. It shouldn't be expected, on its own, to reverse hair loss, but I can certainly see it stopping hair loss in its tracks for individuals who catch it early. It's good for everything. Maybe higher doses (6-8g) a day could spur a full reversal of hair loss, if the hair loss is relatively recent, but such high doses need to be taken with caution, including supplementing with lots of gelatin and vitamin k2.