Your Liver Makes Its Own Sugar — And That Changes Everything

Here's something that completely changed how I think about blood sugar: your liver makes its own glucose. Not from food. Not from the sugar you ate. Your liver manufactures it from scratch, through a process called gluconeogenesis.

I'd been managing my diet for months — cutting carbs, watching portions, doing all the things my doctor suggested — and my fasting numbers were still creeping up. It didn't make sense. Until I understood what was happening in my liver.

What Is Gluconeogenesis?

Gluconeogenesis literally means "the creation of new glucose." It's a metabolic pathway where your liver (and to a lesser extent, your kidneys) converts non-sugar substances — amino acids from protein, glycerol from fats, and lactate — into glucose.

This isn't a malfunction. It's a survival mechanism. Your brain needs glucose to function, even when you're asleep or fasting. Gluconeogenesis ensures there's always a baseline supply available, regardless of when you last ate.

According to research published in Diabetes Care, the liver is responsible for approximately 80% of endogenous glucose production during fasting states. That means most of the glucose in your bloodstream when you wake up in the morning didn't come from last night's dinner — your liver made it overnight.^[1]

When the System Breaks Down

In a healthy body, gluconeogenesis is tightly regulated. Your liver produces just enough glucose to keep things running, and insulin signals it to slow down when levels are adequate.

The problem occurs when this regulation fails. In people with insulin resistance or Type 2 diabetes, the liver often overproduces glucose — essentially ignoring the insulin signals telling it to stop. Research from the Journal of Clinical Investigation has shown that hepatic (liver) glucose production is significantly elevated in people with Type 2 diabetes, contributing substantially to fasting hyperglycemia.^[2]

What this means in practical terms: you can eat perfectly and still have elevated blood sugar, because the excess glucose isn't coming from your plate. It's coming from your liver.

The Environmental Factor

This is where things get interesting — and where I went down the research rabbit hole. A growing body of research is investigating how environmental chemicals may contribute to liver stress and impaired glucose regulation.

A 2019 study published in Environmental Health Perspectives found associations between exposure to certain endocrine-disrupting chemicals — including BPA (found in plastics) and persistent organic pollutants — and increased risk of metabolic dysfunction, including impaired glucose homeostasis.^[3]

The hypothesis being explored by researchers is straightforward: when the liver is under chronic stress from processing environmental toxins, its ability to properly regulate gluconeogenesis may be compromised. It's not that the liver "breaks" — it's that the regulatory signaling becomes less precise.

This area of research is still developing, and I want to be clear about that. The studies show associations, not definitive causation. But the direction of the research is compelling, and it helps explain why so many people who "do everything right" still struggle with their numbers.

What This Means for You

Understanding gluconeogenesis changed my approach to blood sugar in a few important ways.

First, it helped me stop blaming myself. If your liver is overproducing glucose, willpower and perfect eating aren't going to solve the whole problem. It's not a discipline issue — it's a metabolic one.

Second, it shifted my research focus from "what should I eat less of" to "what supports healthy liver function." That's a fundamentally different question, and it led me to research on compounds that have been studied for their effects on hepatic glucose production — things like juniper berry extract, berberine, and alpha-lipoic acid.

I'll cover those in separate articles, because each one deserves its own deep dive into the research. But understanding the liver's role in blood sugar is the foundation that makes everything else click.

The Bottom Line

Your liver is a glucose factory, and when it runs without proper regulation, blood sugar rises regardless of what you eat. This isn't widely discussed in mainstream health advice, which tends to focus almost exclusively on dietary carbohydrates. Understanding gluconeogenesis gives you a more complete picture — and points toward a different set of solutions.

As always, I encourage you to discuss any changes with your healthcare provider. But I also encourage you to ask them about hepatic glucose production and what role your liver might be playing in your numbers. You might be surprised by the conversation.