You took it inconsistently which effectively altered your body's ability to adapt to this fluctuating internal state, and shed hair as consequence.
Certain medications take [sometimes] weeks to reach stable blood levels to achieve their desired pharmacologic activity. With regards to finasteride, you need to understand that it will lower your systemic DHT, and any sudden hormonal imbalance will have direct ramifications on hair (hair follicles are very sensitive to hormonal change). In consequence, your body's natural ability to remain stable [homeostasis] will be thrown off until it can re-adjust to this new "low-DHT" environment. I truly believe that this phenomenon is what was responsible for your "side-effects". I'm confident that if you just stick with the treatment, after a few week to a month these "side-effects" will become much less of a problem.
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As an aside, I used quotations "" around side-effects for the simple fact that if you have not gotten blood tests done, it would be scientifically inaccurate to attribute observations to Finasteride alone.
finasteride has a serum half-life of ~six hours with oral bio-avalibility at ~63%.
I will explain what this means the best way I can.
- yadayada ingests 1mg at 0:00 hours.
- 63% of the 1mg tablet (0.63mg) is effectively absorbed into the body. 0:00 hours=0.63mg
- Six hours later, 1/2 of the initial dose remains in circulation.---> 6:00 hours = 0.315
- 12:00 hours = 0.1575mg remains in circulation.
- 18:00 hours = 0.07875mg remains in circulation
- It takes around 6 half-lives for a drug to be fully eliminated
After only 18 hours, Finasteride has become nearly inactive.
THIS IS WHY IT WORKS THE BEST IF TAKEN EVERYDAY.
Albeit, based on this information it seems that maybe twice a day dosing would be optimal, hmmm... food for thought I guess.
Off to the research lab for me.