Short answer: It can in some people. US testosterone labels say that in people with diabetes, testosterone may lower blood glucose and so may lower insulin needs. Trials disagree on whether that matters long term: in T4DM, testosterone shots plus a lifestyle program cut new type 2 diabetes at 2 years, but in a TRAVERSE substudy, testosterone gel did not slow prediabetes turning into diabetes or improve sugar control.
The AndroGel 1.62% label lists insulin as a drug interaction (section 7.1). It says changes in insulin sensitivity or blood sugar control may occur with androgens, and that in patients with diabetes, androgens may decrease blood glucose and therefore may decrease insulin needs. The Depo-Testosterone label carries the same line in its drug interactions section.
The labels do not give a size for the drop or say how soon it can happen. They flag it so that people on insulin, or on pills that push insulin release such as sulfonylureas, and their prescribers know blood sugar may move.
T4DM was a 2-year Australian trial of 1,007 men aged 50 to 74 with a large waist, testosterone at or below 14 nmol/L without a diagnosed testosterone disorder, and either impaired glucose tolerance or newly diagnosed type 2 diabetes. All joined a lifestyle program, and men got either testosterone undecanoate 1,000 mg injections or placebo every 3 months.
| Measure | Testosterone | Placebo |
|---|---|---|
| Type 2 diabetes on a glucose tolerance test | 12% (55 of 443) | 21% (87 of 413) |
| Change in 2-hour glucose | -1.70 mmol/L | -0.95 mmol/L |
| Hematocrit over 54% (safety trigger) | 22% (106 of 491) | 1% (6 of 484) |
The authors said rising hematocrit might limit treatment, and that long-term safety and heart effects still needed study.
A substudy of the TRAVERSE trial looked at men aged 45 to 80 with hypogonadism (low testosterone with symptoms) and prediabetes or diabetes, given 1.62% testosterone gel or placebo gel. Among 1,175 men with prediabetes, the share who progressed to diabetes did not differ significantly: for example, 10.1% vs 14.6% at 24 months and 13.4% vs 15.7% at 48 months, with an overall test that was not significant.
Among the men who already had diabetes, remission rates and changes in glucose and HbA1c were similar on testosterone and placebo. The authors concluded that testosterone alone should not be used to prevent or treat diabetes in men with hypogonadism.
The two trials differ in the product, the dose, the people enrolled and whether a lifestyle program came with it, which may explain part of the gap.
The label wording is the practical part: blood sugar and insulin needs may change. If you use insulin or a sulfonylurea, the prescriber who manages your diabetes should know when testosterone starts or the dose changes. Testosterone can also raise hematocrit, which is checked on blood tests during treatment.
Keeping glucose readings, doses and lab results together makes any pattern easier to see. Dose Track logs each testosterone dose and lets you note readings and how you feel.
Read more on Dose Track: AndroGel side effects · Depo-Testosterone side effects · Blood sugar: what the evidence shows · Hematocrit monitoring on TRT · What is hypoglycemia?