Androgenetic Alopecia in simple terms is "hair decay". When a person's genetic light-switch turns on, then the genetically susceptible hair under the influence of DHT (dihydrotestosterone) progressively miniaturizes until it cannot be seen by the naked eye.

I see this process of "hair decay" similar to "tooth decay" because they both occur as you age and are progressive disorders. The use of Propecia in the prevention and treatment of "hair decay" is analogous to toothpaste in the prevention and treatment of "tooth decay".

Using this analogy,

What should be started first: Propecia or Hair Transplants?

The answer quite simply is Propecia. Do patients tell their dentist that they are not willing to brush their teeth with toothpaste, but will just have their cavities filled in when they get "tooth decay"? It doesn't seem logical. This is similar to the patient who is unwilling to use Propecia, but just wants their doctor to fill in the areas of "hair decay" (i.e. - perform a hair transplant).

When is it best to start treatment to prevent "hair decay"?

With toothpaste, patients shouldn't wait until they only have a few teeth left in their mouths before they start brushing their teeth. Similarly, for best results with Propecia, patients should not wait until they are extensively balding before they start using Propecia. The hair count studies performed on Propecia versus Placebo confirmed that the sooner a patient starts Propecia the higher his hair counts will be. Figure 2 shows this study. The yellow line is patients that were given Propecia at the beginning of the study, and they showed a significant increase in their hair counts over time. The red line is the patients that were placed on the Placebo (sugar tablet) and they showed a significant decrease in their hair counts over time. The green line is the patients who were first placed on the placebo for 1 year (with a significant decrease in the hair counts) and then were switched over to Propecia for the next 4 years (with a significant increase in hair counts), however these patients never caught up to the hair counts of the patients that were started on Propecia from the beginning. This demonstrates that even waiting one year makes a difference.

Is there a point of time when using Propecia is worthless?

Toothpaste is worthless when there are no more teeth left in your mouth. Propecia becomes worthless when the patient no longer has any genetically susceptible hair left on his head.
It is important to make sure the patient's expectations are in line with what Propecia can realistically do.
" If the patient is significantly balding and is hoping Propecia can stop the further progression of his hair loss, he has a realistic chance Propecia is going to meet his expectations
" If the patient is significantly balding and is expecting Propecia to give him a full head of hair, he is unrealistic about what Propecia can accomplish and should not go on Propecia.

How long does a patient need to be on Propecia?

If you stop taking Propecia you will lose any results that were attributable to Propecia, and you will lose the benefit of it preventing and/or delaying "hair decay". Similarly, if you stop brushing your teeth you will lose the benefit of the toothpaste in preventing and/or delaying "tooth decay".