When the Shot Hits the Heart: How GLP‑1 Changes Desire, Obsession, and Love

By Limor Weinstein

“He used to look at me like I was the only person in the world,” says Lisa, a 42-year-old mother of two boys who spent ten years in an unhappy marriage before finding herself in a whirlwind romance. “For four years, I was his everything. He traveled across countries to see me. Every weekend, he made me breakfast in bed. He couldn’t go a day without telling me he loved me. And then… in what felt like a blink, it was over.”

For years, their relationship was what many dream of: passion, devotion, and intensity. He adored her, and she felt chosen in an intoxicating way. But as Lisa told me her story, her voice softened: “It wasn’t just love. It was… something else. He was addicted to me. And then one day, it was as if he had flipped a switch from obsession to nothing. He blocked me. A week later, I found him on dating apps.”

When Love Crosses into Limerence

What Lisa described has a name: limerence. Limerence is when love tips into obsession.

• It’s fueled by the brain’s dopamine “reward” circuits—the same ones tied to cravings and addiction (Tennov, 1979).

• It feels electric: constant thoughts, a rush when they respond, despair when they don’t.

• But limerence isn’t steady love; it’s a fragile, chemical loop. And when that loop breaks, the crash can feel just as extreme as the obsession (LivingWithLimerence, 2020).

For Lisa, that “break” wasn’t emotional. It was biological.

The Twist: When Chemistry Meets Chemistry

In the last six months of their relationship, her boyfriend started injecting a GLP‑1 medication (like Ozempic, Wegovy, or Zepbound). At first, it seemed harmless. Then, everything shifted.

He lost a significant amount of weight. He became more tired. The emotional intensity that once defined their love began to cool. The man who made her breakfast in bed every weekend and couldn’t live without her suddenly felt distant. Within weeks, he ended things abruptly and moved on to dating apps.

“I couldn’t make sense of it,” Lisa said. “How do you go from being obsessed with someone for years to walking away like it was nothing?”

The Science Behind the Shift

GLP‑1 drugs do more than curb hunger; they also affect the brain’s reward system. These medications lower dopamine activity in the very circuits that drive cravings, pleasure, and even obsessive attachment (Lengsfeld et al., 2024).

• Lower dopamine spikes: GLP-1 can mitigate the intense highs and lows associated with craving and reward (Dimitri, 2025).

• Emotional flattening: Some people report a kind of “numbness,” less urgency around food, alcohol, and sometimes even relationships (Visvabharathy, 2025).

• Sex and intimacy: Surveys show mixed effects—some feel more confident and sexually alive, while others report reduced libido and emotional connection (Kinsey Institute, 2025).

In a relationship built on limerence, muting those dopamine surges can cause passion to disappear, not because the love wasn’t real, but because the brain’s chemistry has literally changed.

From Obsession to Disconnection

For Lisa, the heartbreak wasn’t just losing him. She felt like she was losing the story they thought they were writing together.

“Was any of it real?” she asked me.

The answer: yes, the feelings were real. However, the relationship was built on dopamine-driven highs, rather than steady, grounded love. When GLP‑1 quieted those reward circuits, the loop broke, and so did the illusion of permanence.

Red Flags to Watch For

1. Love that feels more like intensity than safety.

2. Grand gestures fueled by fear of losing you, not connection.

3. Extreme swings: obsession one day, cold withdrawal the next.

4. A relationship that collapses when boundaries are set.

Why This Matters

GLP‑1 medications are reshaping more than bodies; they’re reshaping relationships. They can bring confidence, freedom from compulsive patterns, and even better intimacy. However, they can also expose when a relationship was built on limerence rather than genuine emotional safety.

If This Feels Familiar…

If you’ve felt a sudden shift in your relationship after starting GLP‑1, or you’ve been on either side of an obsessive love story that turned cold, you are not alone. These changes are not your fault; they are rooted in fundamental neurobiology.

If you want to speak with a mental health professional, gain a deeper understanding of your relationship patterns, and learn how to cultivate healthy, lasting love-

CONTACT us today.

Have you experienced something similar?

We’d love to hear your story. Whether it’s about GLP‑1, obsession, or limerence, share your experience in the comments or send us a private message. Your story might help someone else feel less alone.

Sources

Tennov (1979); LivingWithLimerence (2020); Lengsfeld et al. (2024); Dimitri (2025); Visvabharathy (2025); Kinsey Institute (2025).