How long after injection does plasma level peak ?

If a drug's half life in N days, how long after injection does the level in your blood peak ?

I know the half life describes the rate at which it leaves but Ive never heard any explanation of how long it takes to enter the blodstream.

i think it takes a few weeks for plasma levels to hit their peak... after several injections. i'm gonna bump this for einstein...

around 4-5 weeks with long esters..and around 3-6 days with short esters

i think their is a sticky about this very sub.

Quote:

---

Originally Posted by decadbal

i think their is a sticky about this very sub.

---

i checked it out that sticky is a 100 line fomrmula that simple ycould have been stated

X = log2N where X = amt in blood and N is # of days AFTER peak levels achieved

But this (and his long winded one) formula is only correct if understood that N is # days after peak levels achieved, NOT # days after injection as his table states. Other than that he is on the right track.

The querstion that none seems to have an answer for is,

Based on the half life, can you compute the # of days after injection till blood levels peak?

Or is peak onset NOT a function of half life ?

Quote:

---

Originally Posted by barbarian

around 4-5 weeks with long esters..and around 3-6 days with short esters

---

Thanks B, this helps. Im thinking I might start my 20 week cycle with Prop then when I get frontloaded switch to Cyp mid cycle then prop at end so the stuff leaves me faster and get into PCT sooner.

Knowing these times helps me.