I love supplements, the idea that a little pill can improve your well-being. It mostly doesn't work, but there are a few I've found of value.

Protein powder - great for making DIY replacement meals / weight loss, saving money on meat

L-theanine - an ingredient found in tea, it's why tea is more calming than coffee. This one is relaxing, great for anxiety, and fast acting. The downside? I've noticed it can cause rebound anxiety. Still very few supplements actually have an immediately noticeable effect.

Magnesium l-threonate - a novel form of magnesium, not found in nature. It's magnesium chelated with threonic acid, a metabolite of ascorbic acid (vitamin C), and unlike other magnesium supplements this one will cross the blood brain barrier. Besides helping with the usual things magnesium is used for (like sore muscles / cramps), this one is good for your brain. I swear I can feel it acting almost immediately too, really helps with 'brain fog.'

Accumulating experimental evidence continues to suggest that magnesium plays a critical role in a number of neurological conditions including headache, stress, alcohol/drug intoxication, acute brain injury, seizures, Parkinson’s disease and Alzheimer’s disease. Simple administration of a magnesium salt in these conditions has not always been therapeutically successful, with a number of studies showing poor penetration of serum magnesium across the blood brain barrier. Several studies have since demonstrated that using a carrier such as polyethylene glycol can address this, simultaneously reducing the dose of magnesium required to achieve the desired central effects while at the same time attenuating deleterious peripheral effects. Alternatively, administering a more permeable magnesium salt, such as magnesium threonate, is seen as the preferred option in more chronic neurological conditions, with positive results having been achieved in experimental models of Alzheimer’s disease.

https://www.researchgate.net/profile/Robert-Vink-2/publication/309905257_Magnesium_in_the_CNS_Recent_advances_and_developments/links/5930ad83aca272fc55e172f4/Magnesium-in-the-CNS-Recent-advances-and-developments.pdf

Magnesium is a laxative in all forms, so don't take too much at once or you'll shit yourself.

Iodine - another one that's good for the brain, also gives me a fast acting feeling of a brain boost like the magnesium. I use apply some iodine I have for disinfecting cuts on my skin since I don't have a proper oral form. Seems to work just fine being absorbed that way.

Potassium chloride - If you get muscle cramps the three main culprits mineral wise are potassium, magnesium, and oddly enough calcium. This is a tricky one though because too much is really bad for your heart, it can actually kill you. Potassium supplements by law can't supply more than 3% of your RDA but by buying salt substitute (i.e. Nu-Salt) you get a whole little bottle of nothing but potassium chloride. Some meds can cause issues with potassium, be sure to do your research if you're on any.

Calcium carbonate - Tums. Always handy to have a bottle of tums around, and also potentially helpful for muscle cramps, and if I have heartburn I'd rather take this than a drug personally.

Cheap ass generic multivitamin (I use kirkland brand) - these usually have the crappiest and cheapest forms of most things you need. Still, it works more or less as a sort of shotgun approach to many missing vitamins or minerals. This is where I get my vitamin B1 (thiamine) from. That's a very important one if you drink and don't want to cause lesions on the brain that make you tarded. Might be better to just take a vitamin B complex, but so far the multi seems good enuff.

Glucosamine sulfate, chondroitin sulfate, and MSM - I swear this supplement works better for joint pain than ibuprofen usually for me.

Ascorbic acid (vitamin C)- I needed this for a weird bump on my arm. The oxidized form, dehydroascorbic acid, which has to be made as needed because it breaks down quickly, can be used to kill some types of cancer growths. I can't find the study for this right now though. It also just tastes good and ofc vitamin C is thought to help with all sorts of things I won't get into here.

Vitamin D - I'm including this because I take the prescription version since I am deficient in vitamin D. I think it helps in a general sort of way that's hard to put my finger on.

Kratom - I take it for pain, and I don't really recommend people start this if they don't need to because some people get addicted. It makes codeine seem strong, but it is a weak opioid.

That's everything I take that I can think of.