oxymetholone is progestagenic. It has been observed to cause nipple soreness or to aggravate gynecomastia even in the presence of high dose antiestrogens, strongly suggesting that the effect is not estrogenic. That effect can be reduced by concurrent use of stanozolol (Winstrol), which is anti-progestagenic. This progestagenic effect of oxymetholone is only a concern when using aromatizing steroids. With androgens such as Primobolan, oxymetholone stacks very nicely and is a surprisingly friendly drug. In contrast, with testosterone it is a very harsh drug.
Anadrol does not convert to estrogen, and thus antiestrogens are not required if no aromatizable AAS are being used. However, in concert with aromatizing drugs, Anadrol is notorious for worsening "estrogenic" symptoms, possibly by producing progestagenic symptoms which the bodybuilder confuses as estrogenic, or by altering estrogen metabolism, or by upregulating aromatase.