T Nation



I'm seeing alot of people running an AI in their PCT on some other boards. I'd like to discuss this...

Adex and Nolva Combo PCT wouldn't be good since the adex inhibits the nolva.

But, I'm seeing alot of aromasin+ nolva or clomid.

Why would the AI be needed in PCT if the aromatizing drugs are out of the system at that point?

I've heard a few things such as estrogen rebound and that SERMs increase E2 levels.



Why would this be any different than Adex + SERM?

You answered your own question.


Why so brusque, Balla?

OP: Nolva/Adex isn't preferred in PCT because the Nolva inhibits the Adex, not the other way around.

You don't see this same inhibition with Aromisin which is why you'll see it recommended during PCT.

And yes, you use an AI during PCT to control the estrogen rebound.


<---- Not an MD


Thanks Fellas, good to know


Where does this line of thinking come from? Why would a SERM, which only attaches to estrogen receptors, effect the inhibition of the aromatase enzyme to convert T->E? I don't think this is a true statement, and think running a SERM with an AI is a pretty good idea if one is sensitive to SERM side effects caused by the build up of E2 in the body's system, which attaches to receptors not occupied by the SERM.


It's a fairly well known, well documented drug interaction. It's also in the stickies, iirc.

And you're right, running an AI with a SERM is a good idea. But not Adex. Aromisin shows no such interaction with Nolva.

From Drugs.com:

GENERALLY AVOID: Coadministration with tamoxifen may decrease the plasma concentrations of anastrozole. The mechanism of interaction has not been described. In one clinical trial, coadministration of tamoxifen (20 mg/day) and anastrozole (1 mg/day) in breast cancer patients resulted in decreased anastrozole plasma concentration by 27% compared to administration of anastrozole alone. In addition, at a median follow-up of 33 months, the combination did not demonstrate any efficacy benefit over tamoxifen therapy alone in all patients as well as in the hormone receptor-positive subpopulation, and this treatment arm was discontinued from the trial. The pharmacokinetics of tamoxifen and its pharmacologically active N-desmethyl metabolite were not affected.

Other references:

MedicinesComplete: Baxter K (ed). Tamoxifen + Aromatase inhibitors: Stockleys Drug Interactions. RPS Publishing, London, UK,

MedicinesComplete: McEvoy GK (ed). Anastrozole: American Hospital Formulary Service Drug Information. RPS Publishing, London, UK,

Dowsett M, Cuzick J, Howell A et al: Pharmacokinetics of anastrozole and tamoxifen alone, and in combination, during adjuvant endocrine therapy for early breast cancer in postmenopausal women: a sub-protocol of the 'Arimidex and tamoxifen alone or in combination' (ATAC) trial.. Br J Cancer (2001) 85 (3/Aug 3): 317-24


Interesting. Looks like I was mistaken. Do you know if a similar trial was performed with serm + aromasin?