Is It Chemistry, Or Is It Love?

You know that feeling you get when you meet someone and, for reasons you can't quite explain, you feel an undeniable pull toward them? If you're single, it can be exciting, almost riveting as your heart races, your cheeks flush, and your mind starts imagining what could happen —Is there a date in the future? A few dates? A relationship? And if you’re already coupled, you might feel a twinge of worry—What does this chemistry with this other person mean about my relationship with the person I’m with?

Imagining a future with this person with whom you have strong chemistry if you’re single, and wondering what it all means about your relationship with your partner if you’re partnered are both absolutely natural and normal responses. And they beg an important question: What is chemistry? Where does it come from? And what’s it got to do with love?

Let’s get into it.

What is Chemistry & Where Does It Come From

We can think of chemistry as that magnetic force that seems to attract and pull you toward another person. It's the flutter in your stomach, the excitement of being near them, and the racing heart beat. Attraction and chemistry involve powerful biological, emotional, psychological, and relational processes in the body and brain, including a physiological cocktail of chemicals—cortisol, epinephrine, and dopamine— that fire off when you're near someone who captures your attention in this way. And, they also commonly comes with preoccupying thoughts, strong emotions, and powerful infatuation. You can thank the accompanying low levels of serotonin in that physiological cocktail for that.

The thing about not enough serotonin... It makes all of your critical thinking skills go on vacation. Bye-bye. No critical thinking here. So, when someone comes around that mesmerizes you, you are pulled towards them like a rubber band, unable to see their bad traits. And it’s not necessarily because they’re the Prince Charming or Princess Pretty you’ve been waiting for your entire life!

The thing about not enough serotonin? It makes all of your critical thinking skills go on vacation. Bye-bye. No critical thinking here.

Strong emotional reactions like those that come when we feel mesmerized by someone’s presence, scientists say, come thanks to our brain’s ability to store unpleasant memories of problems past. Because our brain stores and values unpleasant memories to protect us, these memories are more easily activated.

Chemistry, then, has roots in something deeper. Sometimes it can also be influenced by familiarity. Certain people may unconsciously remind us of relational dynamics, emotional experiences, attachment patterns, or nervous system states we experienced earlier in life with our caregivers or other family members — even if we don’t immediately recognize it consciously. That doesn’t automatically mean the connection is unhealthy or doomed. But it can help explain why some relationships feel unusually intense, magnetic, emotionally activating, difficult to let go of, or immediately familiar and have you (often mistakenly) exclaiming “Whoa, this person is my perfect match!” or “I’ve finally met ‘the one’!”

But here's the thing: If the people you spent your time around in childhood represent the kind of person (in terms of personality, values, and responses to conflict) that you really want in a romantic partner, then that person would be a good match. But more often than not, that’s not the case (it’s the rare lucky person that consciously says, “I want to marry someone like my mom/dad”) and the person we notice incredible chemistry with ends up being quite the opposite of a great match.

In fact, most people would say that the last thing they want is someone who resembles their mother, father, or primary caregiver, yet there they are, mesmerized by someone who is similar to these very people in some way. Because when that rush of feel-good chemicals kicks in, well, your critical thinking takes a back seat. Suddenly, you're overlooking their less, completely missing the potential for unhealthy patterns to emerge own the road, and turning what could be a growing, balanced interest into an overwhelming infatuation.

This might not be love. It might just be chemistry doing what it does. Because intense chemistry and lasting love are not always the same thing — though they can overlap.

What is Love & Where Does Love Come From

Love… it’s more than simply a chemical reaction. It doesn't come from a quick surge of adrenaline or a rush of dopamine and it doesn’t happen overnight— instead, it tends to deepen over time through shared experiences, emotional safety, honesty, repair, friendship, trust, mutual care, attraction, vulnerability, and the ways two people continue choosing one another again and again across different seasons of life. To build a connection that’s based on mutual understanding and appreciation as opposed to pushes and pulls is like a construction project. You might create the plan in a number of weeks, but the building of it takes years. It happens slowly and steadily, brick by brick.

Love is like a successful construction project. You might create the plan in a number of weeks, but the building of it takes years.

What Does Chemistry Have To Do With Love?

So when you ask what chemistry has to do with love, I say “it’s unclear” because chemistry alone is not necessarily a reliable indicator of compatibility, emotional safety, or lasting love. The literal chemistry that leads us to feel pulled to someone might mean a fantastic physical relationship with just the right amount of sexual tension but in many cases, it doesn’t predict a healthy, loving relationship. Sure, we need some passion, romance, and to feel drawn to someone, but when it comes to finding a relationship that will be healthy and long-lasting, the person whose familiarity reminds us of our past often couldn’t be further from an ideal match.

You see, if you get into a long-term relationship with this person, the chemistry might blind you from noticing that they’re just as unpleasant to be around, or just as controlling, just as unavailable, or just as [fill in the blank] as mom or dad were (these are just examples), and you will relate to them with the same (often dysfunctional) patterns as you learned in relating to mom or dad as a kid. Our partner will be doing the same; after all, they were unconsciously drawn to us for reasons similar to why we were drawn to them. Take two people who were chemically attracted to each other who each have dysfunctional patterns of relating (e.g., poor communication, disrespect, poor boundaries, lack of cooperation) and you’ve got a recipe for a really challenging future. Without awareness, communication, reflection, healing, and mutual effort, these familiar patterns can sometimes create really painful relational dynamics as time goes on.

But don’t blame yourself… One of the tricky things about intense chemistry is that it can temporarily narrow our perspective. When we feel mesmerized by someone, we may overlook incompatibilities, minimize red flags, idealize them, or become more focused on the feeling itself than on who the person actually is.

Why Strong Chemistry ⧣ Lasting Love

As time passes and two people get to know each other better, the initial intensity of attraction often changes over time. The intense attraction fades, and, all of a sudden, you think “the love has faded”. Well, the love hasn’t faded but the initial chemistry, lust, and attraction has. What remains — or deepens — depends on the emotional foundation of the relationship itself.

In a healthy relationship, when the initial spark is gone, what's left is the foundation of love— the respect, the care, the friendship. But, in our world, we often mistake strong chemistry for love and build lives with others according to strong chemistry while disregarding the building blocks of love. And chemistry without the building blocks of love is just chemistry. And if this is the case, what’s left in the relationship or marriage when the chemistry is gone.

This is why so many relationships that begin with strong chemistry eventually fizzle out. Chemistry alone can't carry the weight of a healthy, long-term relationship. It's love—the kind that's built with intention and effort—that will see you through.

The truth is, relationships are rarely simple. Human connection is layered, emotional, biological, relational, psychological, and deeply personal. Sometimes chemistry points toward genuine compatibility. Sometimes it points toward familiarity, longing, unresolved wounds, or nervous system activation. And often, it’s a mix of many things at once.

Part of the work of building healthier relationships is learning how to slow down enough to notice the difference between intensity, familiarity, attraction, emotional safety, compatibility, and love — and to approach ourselves and our patterns with curiosity rather than shame as we do.

A lot of this begins with understanding ourselves more deeply: the parts of us that long for connection, fear rejection, chase intensity, confuse familiarity with safety, or struggle to trust ourselves in relationships. These are some of the kinds of inner patterns we work with inside my course Happy from the Inside Out®.

And if you’re looking for a space to have more honest conversations about relationships, dating, emotional intimacy, and being human alongside other thoughtful people, my Heart Share Circles are another place where we explore these topics together.

Note: This article was originally written several years ago and has been lightly updated to reflect the evolution of my work, perspective, and offerings.