Lots of scholarly articles on the web say no. But that's not my experience. I can drink two double lattes (35g) and still get to sleep, but 5 ounces of black coffee (7g) gives me the jitters. What do others think?

five oz of drip coffee probably has more caffeine than your espresso shots. Has nothing to do with milk.

BaristaMcBob wrote:Lots of scholarly articles on the web say no.

I'm not a milk drinker. But when I googled "coffee caffeine absorption milk" I found a March 2021 review of the existing literature ("Addition of milk to coffee beverages; the effect on functional, nutritional, and sensorial properties", A. Rashidinejad, and others). Unfortunately it is firmly behind a paywall. But here is a very brief excerpt:

"While the effect of milk addition on the bioefficacy of caffeine is currently unknown..."

How do you figure that? A single serving of coffee is about 7g. A double espresso, for me, is 17g. Does a 3 minute brew time extract more caffeine than a 30 second pressurized extraction? Just asking

It's often said that a cup of coffee has more caffeine than a cup of espresso. And typically that's true. But there's just no way that's true in your example.

Have you ruled out food in general as some sort of moderating effect? One might imagine it to slow down absorption, just like with booze, limiting the maximum blood concentration. So can you eat a meal with your 5oz cup and still get jitters and be an insomniac?

BaristaMcBob wrote:...but 5 ounces of black coffee (7g) gives me the jitters.

I don't drink regular coffee, does one only use 7g of grounds for a cup of coffee??

7g of grounds in 5oz of liquid is around 1% TDS, a little on the weak side. The SCAA "ideal" is 1.25% and your local cafe probably brews cups that are 1.4% or stronger. But whatever.

7g of coffee would result in a pretty small dose of caffeine, on par with a can of Diet Coke.

Pressino wrote:To answer the OP's question, milk doesn't damp caffeine absorption, but non-dairy creamer + sugar does, according to a study done about a decade ago. The total amount of caffeine absorbed by the body is the same, but the absorption rate is slower with NDC + sugar (and I'm not sure if the sugar makes any difference). 8)

Which study?

There was a small study (12 participants) in 2010 that examined the effect of non-dairy creamer vs milk on chlorogenic acid absorption. Was that the study you remembered? Or was there another one that looked at caffeine?

Nondairy Creamer, but Not Milk, Delays the Appearance of Coffee Phenolic Acid Equivalents in Human Plasma
M Renouf and others, Journal of Nutrition, 2010