When we talk about love and lust, we’re diving into the feelings that make human connections so complicated. It’s not just about the excitement and nervousness; there’s a whole emotional landscape at play. And that’s not to mention the explosion of chemical reactions happening all around your brain and body, making you feel a million things all at once.

Lust and love might seem like similar experiences on the surface. Truthfully, they aren’t all that different from a chemistry standpoint. They both cause faster heartbeats and sweaty palms, and they both make your brain light up like a Christmas tree. If we look deeper, however, we can see they have some key differences.

The Chemistry of Lust

Let’s start by talking about lust, which is like a powerful magnet that can pull people together. A mix of hormones, neurotransmitters, and chemical reactions are in the driver’s seat. These all contribute to our libido, or our sex drive, and they play a crucial role in stoking the fiery feelings of lust.

Before you even speak to your intended mate, the communication has already begun. A mix of chemicals called pheromones act as chemical messengers in the air between you and your possible bedmate. All over the animal kingdom, smell is hugely important in mating. Pheromones can convey things like health, fertility, and evolutionary fitness.

Scientists disagree on how important pheromones are to human sexual response, but there is evidence to suggest that our olfactory system—that’s our sense of smell—can read these signals and use them to decide the viability of our intended mate.

Testosterone is closely associated with male libido. This means that when the heat turns up in the bedroom, testosterone spikes. In female libido and health, testosterone plays a relatively small but important role as well. It works with estrogen, the most important sex hormone for women, to increase sexual desire and arousal.

Increased estrogen production is also the reason many women feel an increase in their libido around ovulation, about two weeks after their menstrual cycle begins. This is when estrogen production peaks, before slowly declining through the latter half of the cycle. This causes an increase in sex drive as well.

All the hormones coursing through you create a mix of intense feelings, drawing you in. Then dopamine, one of the pleasure-causing chemicals in our brains, rushes in, making you feel euphoric. It works with oxytocin, the “cuddle hormone” to make sex feel rewarding, driving you to keep going.

A burst of oxytocin floods your brain during orgasm. This helps make a one-off romp feel more intimate. Oxytocin fosters feelings of trust and attachment. This contributes to a sense of connectedness. It also helps explain why you might feel emotionally closer to a partner after some time in the bedroom.

A chemical cocktail in your brain is telling you this is perfection, but don’t trust it blindly. The feeling of lust is all about temporary, physical attraction. A passionate introduction doesn’t always mean there’s a deeper connection.

Love vs. Lust

So, what’s the difference between love and lust? One big thing is timing. Lust peaks in the early, exciting phase of a relationship, fueled by the novelty and mystery of a new partner. It activates the brain’s reward center, making you feel euphoric and ready for another hit. This sudden rush of passion may create a strong initial connection, but according to relationship expert Dr. Terri Orbuch, lust always fades over time.

Love can certainly grow from this place. However, lust alone cannot form the basis of a lasting romantic connection. Lust puts us into a heightened state of arousal, making it difficult to sustain over a long period. In simple terms, what goes up must come down.

Unlike lust, love sustains itself over time through a more steady and consistent release of oxytocin and serotonin. When you’re in love, parts of the brain associated with attachment and memory light up too. However, the differences aren’t just chemical; Dr. Orbuch says that love and lust are two completely different emotions.

The Complexity of Love

While lust is about sexual gratification, falling in love is about deep emotional attachment. This is the basis of a lasting connection that goes beyond the temporary excitement of lust. According to Dr. Orbuch’s research, there are four key features that distinguish love from lust.

The first of these is connection. While lust makes it easy to connect with our partner, people in love want to connect with each other’s friends and family as well. Whether we like it or not, the approval of our loved ones is a big factor in our choice of relationship. We want our loved ones to spend time with our partner and be impressed by them.

The second sign is something Dr. Orbuch calls mutuality. Someone in a relationship with mutuality might say things like “We went to the store” instead of “I went to the store.” Their partner is a main character in their story, because their lives are intertwined. Lust won’t drive you toward mutuality; thinking of yourself as part of a couple is a sure sign of loving feelings.

The next difference Dr. Orbuch says to look for is self-disclosure. Lust is a temporary feeling that doesn’t leave much space for emotional vulnerability. As you fall in love, you’ll begin to trust your partner with more intimate details about yourself. This could be anything from discussing your hopes and dreams to confiding something private.

Finally, Dr. Orbuch says that you’ll know it’s love when your relationship has a degree of interdependence. She describes this as the influence you and your partner have on one another. This might mean asking for their advice about a big decision. It could also look like asking them for support when you’re going through a hard time or calling to celebrate your successes.

Please note that this is different from codependency. In any relationship, it’s important to maintain a sense of individuality and to be present in your other relationships. At the end of the day, you should still be making your own decisions in a healthy relationship. Your partner should add to your life, not take over it.

Love and lust might start from a similar place, but they have different purposes in our lives. Lust might spark the initial attraction, but it’s love that keeps the fire burning. Neither is morally better; in fact, both are important in our emotional lives. The key is finding a balance and learning the difference between these emotions. So, the next time you feel passion flaring up, ask yourself—is it the temporary thrill of lust or the lasting warmth of love?