Victoza® and sexual function

What the product information contains

The US label and the European summary list no sexual reactions such as reduced desire, erection problems or orgasm changes for Victoza®. ^[1][2] The only measured row comes from Canada, whose monograph prints every event above 1% in each trial. ^[3] In trial 1842, a 52-week study of Victoza® 1.8 mg with metformin and an add-on of insulin detemir in some patients, erectile dysfunction was reported by 1 of 159 people (0.6%) without insulin and 2 of 163 (1.2%) with it. ^[3] There was no placebo arm, and the row did not appear in the other Canadian trial tables. ^[3]

On fertility, the US label reports no direct effect on male fertility in rats at exposures about 11 times the human level, and Europe says animal studies showed no harmful effects on fertility apart from a slight decrease in live implants. ^[1][2]

What small liraglutide studies found in men

Two studies looked directly at sexual function with liraglutide, and both pointed towards improvement. In a retrospective real-life study of 43 men with type 2 diabetes, obesity, low testosterone and erectile dysfunction, men who did not reach their blood sugar target on testosterone and metformin had liraglutide added for a second year; their erectile function scores, testosterone and blood sugar improved further. ^[4]

A second study gave 110 men aged 18 to 35 with obesity-related low testosterone one of three treatments chosen by whether they wanted children; the group on liraglutide 3 mg had better erectile function and higher testosterone after 4 months than the other groups. ^[5] That dose is the Saxenda® dose, not Victoza®’s, and neither study had a placebo group or random allocation, so both can only suggest a direction. ^[5]

No study in this search looked at sexual function in women on Victoza®.

Diabetes as the bigger factor

NIDDK explains that high blood glucose can damage the blood vessels and nerves involved in sex and bladder control. ^[6] More than half of men with diabetes develop erectile dysfunction, and men with diabetes are more than 3 times as likely to develop it as men without. ^[6] Women with diabetes can have low desire and response, vaginal dryness and painful sex, caused by nerve damage, reduced blood flow and hormonal changes, and are more prone to yeast and bladder infections. ^[6]

NIDDK lists factors that make these problems more likely: poorly controlled blood glucose, nerve damage, untreated high blood pressure or cholesterol, overweight, inactivity, some medicines, heavy drinking and smoking. ^[6] MedlinePlus’s liraglutide page names decreased sexual ability in men and women among the nerve-related complications that diabetes treatment aims to prevent. ^[9]

Other causes, and the low blood sugar link

MedlinePlus lists high blood pressure, heart and thyroid conditions, clogged arteries, depression, low testosterone, alcohol, nicotine and some medicines, including blood pressure medicines (especially beta-blockers), digoxin, antidepressants and sleeping pills, as causes of erection problems. ^[7] For women, it lists diabetes, heart disease, nerve disorders, hormone problems, some drugs, stress, depression and relationship difficulties. ^[8] Many of these are common in people with type 2 diabetes.

Victoza® can lower blood sugar too far when combined with insulin or a sulfonylurea, and patients aged 10 and older had more lows regardless of other medicines. ^[1] Because sex is physical activity, NIDDK advises checking glucose before and after, especially if you take insulin. ^[6] Feeling shaky, sweaty or weak during or after sex may be a low rather than a sexual problem. ^[1]

Tiredness, nausea and feeling unwell in the first weeks on any GLP-1 medicine can also dampen interest in sex; this is an everyday explanation, not a listed Victoza® reaction.

Teenagers on Victoza®

Victoza® is approved for type 2 diabetes from age 10. ^[1] Canada reports that in young rats given liraglutide at 2.7 to 8.5 times the exposure seen in patients aged 10 to 17, sexual maturation was delayed in both sexes; at the highest dose, oestrous cycles were slightly longer and recovered after treatment stopped. ^[3] These are animal findings at higher exposures. The US and EU documents say side effects in patients aged 10 and older were similar in type and severity to adults’. ^[1][2] Questions about puberty belong with the prescriber.

What the sources describe

• See your provider if erection problems happen more than a quarter of the time, as MedlinePlus advises. ^[7]
• Keep blood glucose, blood pressure and cholesterol near target, stay active, and stop smoking; NIDDK lists these as ways to prevent sexual problems. ^[6]
• Women with vaginal dryness may find a prescription or over-the-counter lubricant helpful, according to NIDDK. ^[6]
• Do not combine erection medicines with nitroglycerin; MedlinePlus warns that blood pressure can drop. ^[7]
• Avoid herbal sexual-performance products without talking to your provider; MedlinePlus says none has been proven for erectile dysfunction. ^[7]

Victoza® and Saxenda® are registered trademarks of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk A/S.