This song is about making a tough decision, the difficult choices around it, and the guilt following it.
Pennyroyal Tea can induce an abortion when drunk in large quantities. Due to its toxicity, however, drinking a lot of it is very dangerous.
Nirvana played this on their MTV Unplugged special, which was recorded shortly before Kurt Cobain killed himself. The album was released about 6 months after his death, and went to #1 in both the UK and US. (thanks, William - Indiana, IN, for all above)
This was the only song during the MTV Unplugged performance that Kurt Cobain played solo, a decision which might have been made at the last minute given the dialogue by Cobain right before he starts playing. (thanks, Adrian - Brookings, SD)
The reference to laxatives and cherry-flavored antacids implies the song is about heroin addiction. Many junkies have laxatives around to combat the chronic constipation that opiates bring. (thanks, Mark - Gainesville, GA)
A remix of this was scheduled for release as a single, but it was pulled when Cobain died. The few copies that leaked out are now rare collector's items.
The lyrics could be Kurt thinking he's a lazy, weak figurehead who is depressed and sad and wants a new life. Some lyric analysis:
"I'm on my time with everyone" - He was usually late for interviews.
"I have very bad posture" - Childhood Scoliosis made him appear hunched over.
"Sit and drink pennyroyal tea" - This could be a drug he took to calm his stomach pains, but it is also a play on words with penny royalty, meaning a cheap figure head.
"Distill the life that's inside of me" - He wants to cleanse his life and start fresh. (thanks, lucy - ottawa, Canada)
The line, "I'm on warm milk and laxatives." could be about Cobain's dependence on DXM, scientifically known as dextromethorphan, which is available in most drug stores. As a result of consuming so much DXM (in the form of Robotussin), he developed stomach pains. One of the long term affects from this is the deterioration of the kidney and liver. The pain that you get from this physically addicting drug is unimaginable. It drove him to do heroine, which didn't last long so he used other remedies to cure his stomach pain. (thanks, Chris - Libertyville, IL)