Modifiers matching estrogen:

• synthetic,
• natural,
• carcinogenic,
• nonsteroidal,
• active,
• endogenous,
• exogenous,
• steroidal,

Simple categories matching steroidal:

• progestin,
• drug,
• receptor,
• agent,
• hormone,
• cream,
• material,
• compound,
• substance,
• androgen,
• medication,
• substrate,
• estrogen,