The title promises a lab report. "Biological reaction" sounds like something from a science textbook, and the poem plays with that cold phrase for almost its whole length. What it describes is the moment someone looks at the person they desire and their body takes over. Its central idea is that attraction is not really a decision. It is something that happens to the speaker, cell by cell, before thought can step in. And at the poem's close, all that physical turbulence settles into one simple, human sensation: the taste of another person.
Look at the vocabulary of the first stanza. "Cell," "nerves," "stimulation," "electricity," "spine," "fingertips": the speaker keeps reaching for the language of anatomy and physics, as if only a scientific register could cover what is happening. Yet the verbs refuse to stay clinical. Cells are "rising up in a passion," nerves "sizzle," and the body is "roaring to life." Hearing "roaring" and "sizzle" in a description of a body makes the speaker sound less like a person than a machine, or a fire, switching on. Heat runs through the whole stanza ("heat rushes," "warmth," "red hot desire"), and the movement is always outward and upward, from the chest to the spine to the fingertips.
The form helps with this. The first stanza is one long sentence, pushed forward by enjambment so that almost no line ends at a natural pause. The grammar keeps leaning into the next line, which gives the feeling of a surge that cannot be stopped. There is no rhyme and no regular beat, and the lowercase throughout takes away the polish of formal punctuation. The poem sounds like thought arriving in real time. Even the placement of "you" is telling. It first appears at the start of a line, tucked after "in response to," so the cause of everything is almost an afterthought, while the body gets all the attention.
One of the most interesting phrases is "starved crevices which yearn, brimming / with red hot desire." Being starved and brimming at once is a contradiction, but it fits. The speaker is describing emptiness and overflow in the same breath, a hunger that is already full of what it wants. The word "primal" nearby reinforces this, suggesting a need older than words.
Then comes the break. The first stanza ends on "bursting out as," a phrase left hanging, and the second stanza completes it: "i see you smile." The little word "as" is doing quiet work here. It can mean "while," so the burst happens at the same moment as the smile, but it can also mean "in the form of," so the whole build-up of electricity bursts out *as* the smile. Either way, the great pressure of the first stanza is released by something tiny and ordinary.
The second stanza changes everything about the poem's pace. The lines become long and flat, almost prose, and the action reverses: "my body slows with a shuddering jolt." That phrase holds both slowing and shaking, as though the speaker has been hit so hard they come to a standstill. The wording "just as you always do" also matters, since it tells us this has happened before. The smile is familiar, and the effect is still overwhelming. There is something touching in that. The speaker is not describing a first spark but a reaction that familiarity has not dulled, and "just" echoes the opening "with just a glance," so that small gestures bookend the poem.
The last line makes the sharpest turn, from touch and heat to taste: "all i can taste in my mouth is the overwhelming sweetness of you, you, you." The repeated "you" is the first time the poem lets its subject take over the language. Earlier the speaker's body filled every line, and now the other person does, three times over, in a rhythm like a pulse or a stammer. Sweetness is also a gentler idea than the earlier "sizzle" and "red hot." After all the electricity, the poem ends on something soft and almost childlike.
That is what makes it worth reading. Poems about desire often reach for grand metaphors, but this one starts from the body and stays there, and its title sets up a cool, scientific distance that the poem then breaks down. The biological reaction turns out to be about a person, and the clinical label cannot hold what it describes.