Yanwen’s blog

9/21/2026

This is the sixth and final piece about David Phillips’s book High on Life: How to Naturally Harness the Power of Six Hormones and Revolutionize Yourself.

The sixth is cortisol (皮质醇), often called the body's primary stress hormone. Cortisol is a steroid hormone produced by the adrenal glands, which sit on top of the kidneys.

Cortisol plays an essential role in the body's response to stress. When the brain detects a threat or challenge, cortisol helps the body become more alert and mobilize the energy needed to respond.

Its functions include:

1. Responding to stress

When we face a threat or intense pressure, cortisol rises and helps increase the availability of energy. It can raise blood sugar, support blood pressure and cardiovascular function, and temporarily shift resources away from less urgent processes such as digestion and reproduction.

A short-term increase in cortisol can therefore be useful. It helps us become alert and focused when something requires immediate attention.

The problem is persistent stress. When the body's stress system is repeatedly activated or its regulation becomes disrupted, it can contribute to problems such as:

• Sleep disruption

• Anxiety and irritability

• Difficulty concentrating

• Weight gain and metabolic problems

• Higher blood pressure

• Problems with learning and memory

2. Following a daily rhythm

Cortisol also follows a natural circadian rhythm. It is normally higher in the morning, helping us wake up and become alert, and gradually declines during the day, reaching lower levels at night.

3. Other important functions

Cortisol also helps regulate metabolism, blood pressure, inflammation, and the body's response to physical stress.

So how can we influence our stress system?

Phillips offers a surprisingly simple suggestion: write down the things that are stressing you.

Too much work? Write it down. A relationship that keeps making you uncomfortable? Write it down. Something that has been delayed for months and annoys you every time you think about it? Write that down too.

Once everything is on paper, look at each item and ask: Can I eliminate it, resolve it, reduce it, or simply accept that I cannot control it?

Some things can be deleted. Delete them.

Some things cannot be deleted, but they can be dealt with. Deal with them.

Some problems have been sitting on our mental to-do lists for months. Sometimes simply taking the first step can turn an undefined source of anxiety into a concrete problem that can be solved.

One less unfinished task can mean one less thing burdening your mind.

This may be one of the most practical lessons from cortisol: sometimes we should simply create less of it.

We often think of stress management as learning how to calm ourselves down after stress arrives.

But sometimes the better way is more direct: Remove the stressor.

And perhaps that is a fitting way to end this six-part journey through Phillips's book. We began with dopamine and the desire to move toward something, and ended with cortisol and the wisdom of knowing what to let go.

Six hormones, six Functions: Want. Dare. Endure. Connect. Be content. Let go.

A good life needs all six.

9/20/2026

This is the fifth piece about David Phillips’s book High on Life: How to Naturally Harness the Power of Six Hormones and Revolutionize Yourself.

Today I'll talk about another chemical in Phillips's framework: serotonin (血清素), sometimes described as a chemical associated with mood stability and well-being.

Serotonin is both a neurotransmitter and a signaling molecule in the body. Most of the body's serotonin is produced outside the brain, particularly in the gastrointestinal tract, while serotonin in the brain is produced by specialized neurons.

Serotonin is involved in many functions, including:

1. Mood and emotional regulation
   It is involved in regulating mood, anxiety, and emotional responses and is associated with feelings of calm and contentment.

2. Sleep and the body clock
   Serotonin is a precursor to melatonin and participates in the regulation of sleep and circadian rhythms.

3. Appetite and digestion
   Serotonin plays an important role in gastrointestinal movement and appetite-related signaling.

4. Impulse control
   Serotonin is involved in regulating impulsive behavior and emotional responses.

5. Pain regulation
   It also participates in the body's complex system for modulating pain.

One way I think about the difference between dopamine and serotonin is this:

Dopamine asks, “What else do I want?”

Serotonin is closer to, “I'm okay with where I am and what I have.”

Dopamine can push us toward the next goal, the next achievement, or the next reward. Serotonin is more associated with a stable sense of well-being and contentment.

Imagine that all your friends have achieved something that you haven't. They have advanced further in their careers, bought something you cannot afford, or invested in a stock that made them money.

You look at your own situation calmly and say, That's their path. I'll continue doing what makes sense for me. You are what people say in Chinese, 不攀比 (bù pān bǐ), don't measure yourself against others.

That ability to remain relatively steady rather than constantly chasing what others have is a valuable form of emotional stability.

So how can we support the body's serotonin system?

One simple suggestion Phillips discusses is exposure to natural light. Research has found links between daylight exposure, serotonin-related activity, and circadian regulation. This is one reason getting outside during the day can be a useful habit, particularly when we are feeling sluggish or low.

Instead of leaving it to chance, you can simply put daylight into your schedule. 

A quick summary so far

• Dopamine: I want to do it!

• Testosterone: I dare to do it!

• Endorphins: That hurts, but I can get through it.

• Oxytocin: I feel close and safe with you.

• Serotonin: I'm calm. I have enough.

Perhaps that's why serotonin is such an interesting part of this series.

We spend a great deal of our lives trying to get somewhere: more money, more achievement, more recognition, more experiences.

But a good life cannot consist entirely of wanting more.

Sometimes the goal is not to climb higher. It is to be able to stop for a moment, look around, and feel that where you are is enough.

9/19/2026

This is the fourth piece about David Phillips’s book High on Life: How to Naturally Harness the Power of Six Hormones and Revolutionize Yourself.

Today I'll talk about another chemical in Phillips's framework: oxytocin (催产素), often called the “bonding hormone” or “love hormone.” Oxytocin is a hormone and neuropeptide produced in the hypothalamus and released into the bloodstream by the pituitary gland. It also acts in the brain as a signaling chemical.

Oxytocin is involved in several important aspects of human life:

1. Social connection and trust. It is involved in feelings of closeness, empathy, and trust and plays a role in forming attachments, including parent-child bonds, romantic relationships, and close friendships.

2. Childbirth and breastfeeding. It stimulates uterine contractions during labor and helps trigger milk letdown during breastfeeding.

3. Stress regulation. Oxytocin interacts with the body's stress systems and may contribute to feelings of calm and safety, particularly in supportive social situations.

4. Social recognition. It is also involved in how we recognize and respond to familiar people and social cues.

In other words, oxytocin is closely connected with one of our most basic human needs: to feel connected and safe with other people.

You may have experienced something like this. After a hectic day, you come home feeling stressed and exhausted. You hug someone you love, sit down together, and talk for a while. Gradually, you begin to relax.

Of course, many things are happening at the same time, but physical touch and positive social interaction can activate systems in the brain and body that are involved in bonding and stress regulation, including oxytocin.

It is almost as if your body is receiving a message: This is a safe place. These are people I can trust. I can let my guard down.

We can also deliberately create more of these moments in our everyday lives.

When spending time with children, for example, we can hold their hands, hug them, pat their backs, or simply sit close to them. Physical touch provides the brain with a whole set of signals associated with connection and safety. The same can happen when we hug someone we love, hold hands, show kindness, or spend time with a pet. These seemingly small actions can strengthen our sense of connection and well-being.

But there is an interesting qualification. Oxytocin is not simply a chemical that makes us universally loving and trusting. Research suggests that its social effects can be highly dependent on context. In some circumstances, it may strengthen attachment to people we already identify with while increasing vigilance or defensiveness toward outsiders.

So perhaps the lesson of oxytocin is human beings are built for connection.

In a world where so much of our communication happens through screens, online, we sometimes forget how powerful a hug, a hand held, a warm conversation, or simply sitting beside someone can be.

Sometimes, what another person needs most is a simple message from our presence:

You are not alone. You are safe with me.

Finally, a song comes to me, "...Lean on me, when you're not strong

9/18/2026

This is the third piece about David Phillips’s book High on Life: How to Naturally Harness the Power of Six Hormones and Revolutionize Yourself.

Today I'll talk about another chemical in Phillips’s framework: endorphins (内啡肽). One of the feelings he associates with endorphins is relief.

If dopamine functions like a gas pedal, helping motivate you to start running and reach your goal, endorphins can act more like a painkiller and a reward cushion, helping you cope with some of the discomfort that comes with exertion.

The two can work together. You may feel motivated when you think about going for a run. As you exercise, your body activates systems that help reduce the sensation of pain and discomfort.

Endorphins are natural chemicals produced by the brain and pituitary gland. They are part of the body's broader endogenous opioid system, which plays an important role in regulating pain, discomfort and other physiological processes.

You may have experienced something similar when you first start running or swimming. Your legs ache, you are out of breath, and your whole body seems to be telling you, You're tired. Stop.

When I was young, people sometimes called this 假疲劳—“false fatigue”—meaning that the initial discomfort might ease if you continued exercising for a while. There is some truth to the experience, although not every sensation of fatigue should simply be pushed through.

As exercise continues, especially when it becomes more intense, the body responds to the temporary physical stress in various ways. Among them is the activation of pain-relieving systems, including the endogenous opioid system, which can reduce the perception of discomfort.

This suggests an interesting way to regulate our emotions.

When we are in a bad mood or feeling uncomfortable, our first instinct may be to lie down, withdraw, or do nothing. But sometimes, instead of waiting for our mood to improve, we can give our bodies a small, manageable challenge: take a brisk walk, jog for a few minutes, swim, or do another form of exercise that raises our heart rate.

The goal is simply to get the body moving and give it something else to respond to.

Laughter is another interesting example. Research suggests that genuine laughter can activate the body's endogenous opioid system. In other words, laughter may be more than an outward expression of happiness; the act of laughing itself may contribute to how we feel.

Sometimes we don't laugh because we are happy. Sometimes we laugh first, and feeling better comes afterward.

Perhaps that is one of the simplest lessons from endorphins: we don't always have to wait for our feelings to change before we act. Sometimes, changing what we do can help change how we feel.

When your mind says, “I don't feel like doing anything,” maybe it's time to stand up and take a walk.

Finally, here's a progression across the first three hormones:

• Dopamine: I want to do it.

• Testosterone: I dare to do it.

• Endorphins: I can get through it.

  

9/17/2026

Yesterday I talked about Seasonal Affective Disorder and David Phillips’s book High on Life: How to Naturally Harness the Power of Six Hormones and Revolutionize Yourself.

Today, I want to dwell a little on the next chemical in Phillips’s framework: testosterone (睾酮).

If dopamine is associated with the feeling of “I want to do it”—motivating us toward rewards—testosterone, in Phillips’s framework, is more closely associated with the feeling of “I dare to do it.”

Imagine that you have trained for years to perform a difficult dive. Just as your turn comes, you suddenly feel your legs shaking. You lose your nerve and decide not to jump. That's because you need more testosterone.

This is where the idea of testosterone as a “confidence hormone” comes in. Testosterone is often associated with behaviors and experiences such as competition, exercise, and winning and losing. 

Phillips also suggests that we can sometimes influence how we feel through what we do physically. In other words, instead of waiting for confidence to appear, we can use our bodies to help create a more confident state of mind.

For example, before an important speech, Phillips uses a pre-performance routine. He might stand up, walk around, and adjust his breathing. These simple physical actions can help him feel more prepared and confident before stepping onto the stage.

So the next time you have to do something that makes you feel insecure or nervous, instead of repeatedly telling yourself, “I need to be confident,” try getting your body moving first. Stand up. Walk around. Take a few deep breaths. Do a few push-ups if that works for you.

The point is not that a few push-ups will magically increase your testosterone or eliminate fear. The point is that our bodies and minds influence each other. Sometimes action can come before confidence, rather than the other way around.

We don't always have to wait until we feel brave before stepping onto the stage.

Sometimes, we step onto the stage first—shoulders back, head up, taking the first step—and let courage catch up with us.

More on this tomorrow...