Meth can release 6 times more dopamine than the body can do alone. But for Lupe knowing the truth makes him feel better than meth ever could.

Tarzan was a wild child that lived in the African jungles by the Mangani “great apes;” he later came across civilization only to push it away and return to the wild as a adventurer.

He is basically saying that life is like swinging on a vine; sometimes you keep swinging and sometimes you break the vine and fail.

Also note that this is tied in with the 5th line, where he says

Jungle way of life

NYPD detectives in NYC ride around in unmarked Chevrolet Caprice cars.

The Schwinn Bicycle Company was founded by German-born mechanical engineer Ignaz Schwinn (1860–1945) in Chicago in 1895.

There’s a story behind this line that he describes in page 30 of his autobiography of One Day It’ll All Make Sense:

When I was eight years old, my mother bought me a bicycle. It was the first one I had ever owned. It was a blue Schwinn with racing tires, and I was sure that it was the best bike on the planet. It meant so much to me that for the first two weeks, I hardly even rode it and if I did, I’d spend a half an hour polishing it back up to a shine. The beginning of its third week, I took it on the longest ride yet – about eight blocks, down to the 7-Eleven. I drove it all the way onto the sidewalk right in front of the store window so that it would never be out of my sight. I bought myself a Slurpee and went back to my beloved bike. That’s when they surrounded me: two older kids from the neighborhood – one fat and one skinny – that I didn’t know by name but knew by sight.

(The two kids intimidated him by demanding him to give up the bike… and so he did. It’s a memory with which he’s lived all of his life, and something he considers a “fear of [his] own fundamental weakness” and “a hidden flaw buried deep in [his] own character”.)

Boogie Down Productions. Boogie Down Productions was a hip hop group that was originally composed of KRS-One, D-Nice, and DJ Scott La Rock.

Cannabis Sativa is the plant that weed grows off of.

B.A. (Bad Attitude) Baracus was an A-Team character portrayed by Mr. T. Also, refers to the previous line

“Sour” is referring to Sour Diesel. Sour Diesel is a hybrid strain of cannabis. It is a cross between Mexican sativa and Chemo indica. The strain produces a fast acting, dreamy high that, due to a 90% concentration of sativa, yields excellent cerebral effects. It is best known for its extremely pungent sour scent as well as its uplifting, mood enhancing effects.
Sour Diesel is highly effective in relieving stress, anxiety, and pain, and there is some suggestion that it may be helpful in alleviating the symptoms associated with chronic depression.

All different strains of weed. And if you got weed Redman is going to buy it

Reference to Bob Marley “One good thing about music, when it hits you fell no pain” from Jam Town Rock. Also, weed is used for AIDS patients, and to help people that have pain in general.