I started Biotin after reading posts on this site & researched other UK sites. Some people measure grams - I’m unable to be accurate due to tremors, lack of concentration etc.
Around May, I bought 3 months supply of Biotin tablets from a UK Pharmacy Supplier on the 'net & take 2 tablets three times each day.
Within 3 weeks I noticed lots more energy, great positive moods and fatigue has greatly reduced. In August, I bought 6 months supply & can’t believe the benefits.
Bonus: Hair grows quicker & healthier, nails grow stronger.
I have only just noticed first signs of foot drop has started in last 10 days, so Biotin may have kept it at bay or minimised the effects, or genuinely just progressed within the expectations of PPMS. Sorry I can’t specify benefits of on foot drop yet, but my balance has greatly improved.
I wish you well, would suggest you try 2 months supply after thorough research. Good luck x