Regular cannabis seeds are produced by traditional male-pollinates-female breeding. The offspring will be approximately 50/50 male and female. Growers who want flower discard the males; breeders KEEP the males for crossing work.

Feminized seeds are produced via reversal techniques (silver thiosulfate, colloidal silver) where a female plant is forced to produce pollen. That pollen has no Y chromosome, so all resulting seeds inherit two X chromosomes — meaning ~100% female offspring.

Trade-offs: feminized seeds are convenient for flower growers (no males to cull, no wasted nodes), but they're often less suitable for breeding work — the lack of true male contribution can compress genetic diversity, and reversed pollen sometimes increases hermaphrodite tendency in offspring.

Serious breeders work primarily with regular seeds because they need stable males. Production growers and casual collectors usually prefer feminized for convenience.

Are feminized seeds genetically modified?+
No. Feminization is just chemically reversing a plant's sex hormone expression — no genetic modification.
Why do breeders prefer regular seeds?+
Stable males are essential to traditional breeding work. You can't make new lines without them.