I'm thinking about making a campaign where players with high enough intelligence can make a drug called "Metaphtamine" which can be used to buff yourself with a chance of negative side effects, but can also be used in interactions with NPCs to boost charisma, but I don't know if it's any good. Please tell me if I should or shouldn't.
It can be fun as a wider theme in a campaign
There is a section on about this in the Book of Vile Darkness from 3.5 (BoVD, pp. 41-44) -appropriately- titled Drugs in chapter 3 which is on Evil Equipment.
It has sections on how to incorporate drugs/substances into a campaign, talks about addiction, it explains characteristics such as initial, secondary and side effects as well as overdose. It's worth a read.
Your idea seems fine. It's your campaign, but there is some background to it. Having a read through BoVD will give you a nice insight into how to incorporate it into the campaign. A lot of what's mentioned in the BoVD is not specific to a particular edition so it should work.
I have used this in my campaigns in the past. I also used this idea for a few homebrewed substances which mimicked spells, e.g. Sleep.
It was interesting for the role-playing side of things, too. Some of the party members were pious other run with it as they each decided how their character would respond to using the substances.
Note: Keep in mind that D&D is about enjoying the game and role-play and conviviality. This subject could be potentially triggering/upsetting to one or more members in your campaign. If you are incorporating this theme as a major theme in the campaign, I would have a chat with them to see if they are ok with it, too.
This concept by itself won't carry a campaign
In nearly all editions of D&D, characters already can create potions that boost their abilities with relative ease, if they take the time to do so, and the DM allows it.
But this -whether magic item or drug- is just a side activity. It is not an idea you can build a campaign on by itself. You need antagonists, secrets, and exploration. Think about these for your campaign. The 5e DMG has a lot of solid advice on this, for example on page 25 Creating a Campaign, or in Chapter 3: Creating Adventures.
How drugs can play a role in a campaign
I have played several campaigns where drugs were a topic, for example Monte Cook's Ptolus for 3e. The concept tends to fit better with city adventures. Typically the drugs are dealt by the criminal underworld, causing misery and suffering in the population, and the characters work to stop this. In my experience, this was a solid backdrop for a lower level part of the campaign (tier 1 mostly) and you can draw on inspiration from all the mafia movies you have seen, when playing the NPCs. But the characters themselves were never that interested in taking them for some transient boost.
On occasion one of them was addicted early on, and this was just annoying administrative overhead, to buy the drug and keep him off drug withdrawal symptoms.
At somewhat higher levels characters will have Lesser Restoration or Cure Disease or similar spells to help them end the "interesting" addiction, at which point the addiction aspect becomes entirely meaningless.
As with all themes that run a risk of upsetting your players due to painful real life experiences they may have had, you should check with your players if they are comfortable with this. If they are not, it is best to avoid it.