What Causes Hair Loss
1) Background & Context
Androgenetic alopecia (AGA) also known as pattern hair loss affects more than sixty million men in America and more than forty million women. Interestingly, rather than actual loss, it is now known that AGA is really a process of miniaturization; wherein the affected hair follicles and accompanying structures become smaller and less robust with the passage of time. From a biochemical standpoint, it appears that a key feature of AGA is the conversion of the androgen hormone testosterone (T) to its more pathological metabolite dihydrotestosterone (DHT) via the triggering enzyme 5 alpha reductase. Recently, a number of other triggers have been identified, including certain forms of tissue inflammation: https://www.ncbi.nlm.nih.gov/pubmed/19692448
2) The triggers
There are three things that need to occur in order for one to suffer from AGA. First, genetics, i.e. choosing one’s parents poorly. The more profound the degree of hair loss in your parents and grandparents, the more likely you are to recapitulate the problem yourself.

The disorder manifests in adulthood - six year old children do not suffer from AGA - and is considered a progressive process in that the zone of hair loss worsens over time. In men, the age of onset often occurs in the mid to late 20s whereas in women female pattern hair loss may not become apparent until the late 30s to early 40s.
3) Treatment options that actually work
Until recently, there were no viable treatment options against AGA. In the 1980s and 1990s two drugs became readily available. The first was minoxidil (Rogaine™) and the second, finasteride (Propecia™). While each drug showed positive benefits in slowing the rate of hair loss they also demonstrated significant negative side effects. Interestingly, in its etiology, a disorder known as benign prostatic hyperplasia (BPH) shares a striking degree of similarity to AGA. This becomes relevant as naturally based compounds useful against BPH were successfully tested against AGA: https://www.ncbi.nlm.nih.gov/pubmed/?term=marcovici+and+hair
4) The future
One of the difficulties in progressing toward an actual cure for AGA has been the fact that no animal model exists for the disorder. This tends to limit the tools available to interrogate putative therapeutic targets. However, progress is occurring in several fronts. Because AGA is known as a complex trait disorder (i.e. caused by a number of genetic and epigenetic factors) the first involves recent efforts to develop a cocktail mix of naturally-based compounds with an eye towards creating a therapeutic synergy: https://www.ncbi.nlm.nih.gov/pubmed/26990224
The next option is based on modifying the causative genes, in effect stimulating those ‘hair growing genes’ which have become silenced and down regulating those which are contributing to the onset and progression of AGA. The last option involves recapitulating the entire human scalp hair follicle in vitro — in other words, growing hair in the lab. Here, progress is occurring and the endpoint result should be the ability to take one or two hairs and grow enough new hair to fill in the denuded scalp. Perhaps most intriguingly, the paradigm appears to open the door to the exciting opportunities in this rapidly evolving realm.

Here is a published review article that describes the process in some detail: https://pubmed.ncbi.nlm.nih.gov/28592171/
As progress occurs in each of these areas we will update you as we are able.