Hey Ray

The problem is not giving you too much information. And you didn't give enough. What symptoms are you hoping to address? Which effects are you hoping to potentiate? Which amino acids?

DLPA (d-,l-phenylalanine) is what's called a racemate. It a pretty much 50-50 mixture of the two forms of phenylalanine, the one with the right hand twist (the dextro-, or just d-), and the one with the left hand twist (the levo-, or l-).

You know when you're shaking hands, a right hand fits in a right hand, but a left and a right don't work right? Same deal with these aminos. In Her infinite wisdom, or by a flip of the coin (whichever you prefer), Momma Nature has gone left-handed. All the amino acids that go into proteins, neurotransmitters, etc. are left-handed (if they have "handedness" as a characteristic....some aminos don't).

So, "natural" phenylalanine tends to be pure l-phenylalanine. When humans synthesize phenylalanine, we can't control the "handedness" of the product, and we get a racemic mixture, a tumble of lefts and rights that is 50% l- and 50% d- (usually).

So, DLPA is man-made, and it contains d-phenylalanine, which I just said can't be used for proteins or neurotransmitter synthesis. What's up with that? D-amino acids are not rare in food. We just don't utilize them the same as other aminos. D-aminos are abundant in fermented foods, because bacteria/yeast produce them quite readily. 10% of the aminos in beer are dextral. Aged cheese is full of them. It may be part of the reasong we like the taste so much. We want them.

L-phenylalanine is three steps from dopamine. It can be converted to l-tyrosine, which can then be converted to L-DOPA, which can then go on to dopamine. Dopamine can itself then be transformed into noradrenaline (norepinephrine). And further.

D-phenylalanine cannot fit into the enzyme that converts l-phenylalanine into l-tyrosine, so it hits an immediate dead end in this synthetic route. It does, however, fit easily into the enzyme that decarboxylates L-DOPA to dopamine (and other decarboxylases, which the brain has in abundance), so d-phenylalanine gets converted into PEA, phenylethylamine. That's a feel-good chemical all by its lonesome. It's one of the chemicals in chocolate that is supposed to make you feel good.

All these conversions require B-vitamins, some require vitamin C, and the enzymes require minerals for their structure. So, if you're deficient in folate, pyridoxine, niacinamide, ascorbic acid, zinc, or magnesium, you may not be doing these conversions efficiently. I suspect that is what you were looking for when you were asking about boosting the effectiveness.

With respect to tolerance....I don't think that's the right word for what the body does. It's called feedback regulation. In all of these enzyme controlled processes leading to neurotransmitter synthesis, there are biochemical sensor loops that signal just how much "raw material" and how much "product" is going through the system. If you exceed your body's reasonable need for the products, the enzymes will be down-regulated. You can't manipulate everything just as you'd like.

Another thing that occurs is adaptation. On the first dose of a supplement (e.g. DLPA), a fairly profound effect might be noted. That could be because the body is, at that point in time, starving for that raw material. Or, simply has excess capacity available. Along comes this artificial manipulation of blood concentration (e.g. 2000 mg oral dose of DLPA on an empty stomach), and the enzymes simply jump to work. And you get a sudden effect that you chase after every time you take it. The observeable effect diminishes with time, because your body adapts. That doesn't mean nothing's happening. You've adjusted what you sense as "normal".

You're not likely to ever have such a noticeable effect again. You adapt after each dose.

There are reasonable intakes, and then there are ones that exceed the body's capacity to make good use of the nutrient.

Signs of excess intake include irritability, decreased ability to concentrate, and headache.

What I like about nutrient supplementation is that I've come to have a sort of dialogue with my body. I don't take *anything*, not any nutrient, every day. I'm coming to have a sense of how I might enhance my bodily function with nutrient doses. Averaged over periods of a week or two, my intakes are substantial. But I keep my enzymes hungry, so I don't downregulate them.

That's what works for me.

Lar