S-propyl-l-cysteine, S-ethyl-l-cysteine, S-methyl-l-cysteine

The above versions of cysteine were found to be neuroprotective in a preclinical cell-culture study here: sciencedirect.com/science/a...

S-methyl-l-cysteine was found to be neuroprotective in a preclinical fruit fly study here:


One question is whether the mechanism of action is any different than that of N-acetyl-cysteine demonstrated here:


I have checked into suppliers of the above compounds: I did not find any supplier of the propyl version, one German supplier of the ethyl version and I have asked for a quote, one Chinese supplier of the methyl version listed at $47/kilo = .047/gram which is quite reasonable and I have asked to place an order. China does not have such a great reputation, but I did order Chinese chemical once before and what I got tested out as pure at a local chem lab.

17 Replies

  • So is it a powder that you mix with water and how do you know how much?

  • For starters we need to find a supplier - these chemical houses linked to above would charge hundreds of dollars per dose and would not likely sell to private parties. I am working on that part.

    Yes, it is a powder. Personally I would put it in capsules - there are inexpensive jigs for doing that - or you could mix a measured amount in water.

    As to dosage, I would first start small to check tolerability. The N-acetyl-cysteine (NAC) study used 1200mg/day, which is what I am taking of NAC. Since the noted cysteine compounds are related I would work my way up to something similar to 1200mg/day.

  • They're supposedly different or better than NAC? Is there reason to believe they absorb and cross the blood-brain barrier? These are the two biggest problems in most promising nutrients.

  • I took a quick look and did not see any comparisons of NAC to these others. A more thorough search might yield results. So I do not know whether concurrent use would be additive or merely redundant. This is an important question which I hope to have time to revisit. The molecules are small enough and have some similarity to NAC so I suspect they will cross the BBB.

  • I've got so many potentially good pills that I can't take them all. With no way to compare them to new ideas it kind of saps the desire to learn about them unless someone is making big claims (mannitol nilotinib). On my short list of proven is green tea extract, NAC, magnesium sulfate, melatonin, vitamin D, and nicotine (patches to protect throat). But exercise and low carb diet (lots of olive oil and mayonnaise) seems to be helping me the most. And to keep my iron levels sufficiently high. I probably have just an anxiety/depression disorder (not connected to thoughts) combined with loss of smell, thirst, and sleep. I'm beginning to think weight lifting is the best type of exercise for me, if I'm not able to be outside all day working on something thoughtless like mowing grass and painting.

  • Is it same as Fermented black garlic Extract powder or deferent ?

  • Fermented black garlic Extract powder contains about 3% S-allyl-cysteine which is the variant of cysteine from which the above named cysteine compounds were derived.

  • Aged garlic (AGE) is better.



    You can find the extract on Amazon.com.


  • I found this supplier :


  • Very good. I have requested a quote.

  • I ordered S-ethyl-l-cysteine powder from china , got it 6 days back and began using it from yesterday , its too early to state if there is any beneficial outcome yet I feel that I am more energetic and have less exhaustion during the day probably its the placebo effect .

    I take one gram of the powder blend it with warm water and drink it , it tastes like concentrated Garlic and can irritate weak stomachs .


    I will keep updating .

  • Bone broth is a good and cheap source of l-cysteine and l-proline.


    This company sells a number of chemicals.


  • Weston Price did excellent work and his organization continues it. Interesting you should mention bone broth because I have had tendon & ligament problems lately. On impulse recently I ordered beef soup bones from my organic co-op. The resulting soup was delicious and it did help. I need to do it again.

  • You can make bone broth very easily. You buy about $10 of organic bones and you cook at low temp in a slow cooker for 24 hours. That will give you a big pot of broth to consume in a week. A crockpot can be left cooked unattended. You can also add herbs, carrots and mushrooms in your broth. After 24 hours and it's done, you use a colander to strain out just the liquid. Sometimes the bones are so well cooked that they disintegrate in the broth.

    Anyway, you know that you are successful if your bone broth turns into a jelly in the fridge overnight.

    I get the most jel (collagen, gelatin) from pork leg bone, next is cow bones and least from chicken or fish bones. While I use more pork bone for my broth, I use beef and chicken bones from time to time for variation.

  • Life Enhancement's 'Propel' formula "delivers propionyl-L-carnitine [2000mg/2g] and acetyl-L-carnitine to promote cellular energy metabolism in the body for both men and women. Also made with alpha lipoic acid, this formula helps support sexual health and promotes many other areas of health" Available via several US-based websites for int'l shipping i.e., iherb.com/pr/life-enhanceme... ; life-enhancement.com/shop/p...

  • As it happens I do take these - an excellent alternative to testosterone for male potency. Carnitine is not cysteine however - it lacks sulfur and the molecular structure is different.

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