I didn't know about PC san pedro when I went shopping but I got these guys off a popular auction website... I have one 5,6 and 7 ribbed. My questions are, Do they look like PC san pedros? Are PC pedros worth growing alkaloid-wise? I also was wondering how these look health wise, received them about 4 days ago and these are my first cacti. thanks for any help you can provide

Appears to be PC, but that doesn't mean hope is lost.

What's up with this meme that PCs aren't active?

It isnt inactive (and no one here said it is, lol)
PC has a variable mescaline content on the low end of the pachanoi spectrum.
It also has non-psychoactive accessory alkaloids that some dont like as they just add to the body load.

They look like PC's to me.

They're worth their weight in gold as grafting stock for higher-alkaloid cactus.

They look quite healthy.

Are they rooted? If not, don't water them until they're showing signs of roots.

Also, from the pics, it looks like you might want to amend your soil mixture. 50% potting soil with 50% pumice or perilite is great for Papa Pedro.

Since they are PC, would it be worth drinking in tea after 3+ years? and yeah they are well rooted I spent quite a bit on these guys.. sad to find out they are not the right kind

If I remember correctly, it takes about 36" of PC pach to feel effects, I cannot personally back this claim.

Shopping for cacti online can be confusing when you're first getting into it. Get familiar with with non-PC-pachanoi and bridgesii.

Now that you have PC pachanoi, study it. Remember what it looks like, how the spines look, the angle of the areola, thickness of the ribs, ect.

Your best bet is to look for bridgesii.

pretty disappointed I bought 5 PC san pedros.. I don't think ill be buying pachanot again.. Bridgessi if I buy a cactus in the future.

In addition to buying bridgesii instead of alleged pachanois and suspicious peruvianus, getting seed of known parentage and starting them on pereskiopsis can also be a great tactic for a beginner.
There are seed available from multiple sources and even ebay that are crosses of known good parents, grafting to pereskiopsis will give you two years growth in six to eight months, then its just a couple years on their own roots and you'll have a sizable mass of cactus. Pereskiopsis grows like a weed and its very easy to clone.
I'm up to my damn nipples in cacti because of seed grown plants (it kind of tickles )

A few good parents involved in circulating hybrid seeds are SS01, SS02, J3, N1, Psycho0, Eileen, Juul's Giant, Super Pedro... there are more, just investigate the names you see attached to seed crosses.

From what I've read, that much PC pach will be enough for a few experiences still, so don't worry. It's a nice cactus in any case, fast grower and hardy. If you have good tea technique, I would guess that 16-18" would probably be enough for moderate effects (though it varies a lot), figuring that it's something like .3-.5% dry weight.

There are non-PC plants on auction all the time, you just have to know what to look for.

There is a nice little intro to identifying PC within Hostilis' cacti article in the e-zine
http://the-nexian.me/the-nexian (might be down this weekend due to maintenance)

This might be somewhat useful. I once extracted from 15 pounds of landscaping PC cactus that a constuction worker/psychonaut friend gave me. These were 4 12" cuttings that were extra beefy, and the first step turned into quite a cooking job. In total I got around a gram of mescaline hcl out of it.

if the extract was even close to pure thats not typical from 4' of pc cacti...

Thats the problem with measuring by feet.
Assuming 94% moisture content that was just under a quarter of one percent alkaloid salt yield on the dry weight basis, even without accounting for the possibility that it contained a significant amount of 3,4-DMPE or somesuch, it does fit in the typical PC range of around 0.0-0.33% mescaline.

Length has never really been the primary way I measure cactus. Weight has always made more sense to me. The 1g of mescaline has yet to be washed, but I've pretty consistently found that the weight decreases around 25% after washing.

For comparison, when I extracted from 5.2 pounds of Bridgesii (4 12" cuttings as well), I got about 1.6g of mescaline. After washing this was reduced to 1.2g.

i ordered a penis cactus (bridgessi)from jimz and a peruvianus pup from another source. I know its hard to identify but for the price I figured ide take a shot at it. ill post pics when the new ones arrive in a day or two

welcome to the cacti world!

I have ordered from jimz as well . Great to deal with. Even called to ask if I wanted a top cut or center cut before shipping