Why is taking Loniten a bad thing but 5% minoxidil isn't?

[$tackz]

Applying 5% Minoxidil twice a day is just about the equivalent of ingesting 2.5mg Loniten daily. Somebody applying Minoxidil 5% with Retin-A can absorb over 5mg daily!!

Yet often times when someone posts about how their doctor perscribed them Loniten for hairloss, they get berated or warned against it. Why is this? They are almost the same thing. Both detrimental to people with heart issues either way.

 

[Nashville Hairline]

On your head is different to directly in your bloodstream.

Where did you read 5% minoxidil = 2.5mg Loniten?

 

[$tackz]

On your head is different to directly in your bloodstream.

Not using the figures I posted, it isn't.

Where did you read 5% minoxidil = 2.5mg Loniten?

I said it equals ABOUT that much, and possibly more depending on the person.

Topical minoxidil is absorbed into the blood with an average of 1.4% of the total dose applied, but can range anywhere between 0.3% and 4.5%. Using Retin-A with minoxidil significantly increases that absorption.

 

[Bryan]

Applying 5% Minoxidil twice a day is just about the equivalent of ingesting 2.5mg Loniten daily.

That's true, but see the important difference I cite below!

Yet often times when someone posts about how their doctor perscribed them Loniten for hairloss, they get berated or warned against it. Why is this? They are almost the same thing. Both detrimental to people with heart issues either way.

Don't forget that the speed of absorption may be important, too. Minoxidil is absorbed about 10 times faster after oral intake, compared to topical application. Here's a statement from "Percutaneous Absorption of Minoxidil in Man" (Arch Dermatol -- Vol 121, 1985): "The data cited by Weiss et al are important in this regard. Serum levels of minoxidil ranged from 0.2 to 5.0 ng/mL two to three hours following topical application, but averaged 155.5 ng/mL one hour following an oral dose of 5 mg/day. Thus, it is possible that the slow rate of absorption associated with topical application leads to blood and tissue levels that always remain below a critical 'threshold' value necessary to trigger a toxic reaction."

 

[$tackz]

Everytime I make a thread it gets moved, lol... as far as I thought a topic about minoxidil belonged in the growth stimulant forum. Oh well.

Thanks for the information about the speed of absorption Bryan, I completely didn't factor that into the equation. Have you ever seen anything cited about the absorption rate of Minoxidil when used on skin affected by retin-a?

 

[Bryan]

Have you ever seen anything cited about the absorption rate of Minoxidil when used on skin affected by retin-a?

No, but I don't doubt that you're correct that it increases the systemic absorption of topical minoxidil.

 

[Bryan]

Where did you read that taking 2.5mg daily is equivalent to 1mL twice daily ?

The study I cited earlier makes a similar statement as that. However, read the excerpt that I quoted before: there's a big difference in the SPEED of absorption between those two methods of using minoxidil.