Modifiers matching estrogen:

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

Simple categories matching steroidal:

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