More Natural

there are comments on another's poem per contest
I find that reading out loud helps to make sure rhythm matches.  In a rhymed poem especially, the number of syllables per line, and the syllables that are stressed should be predictable -- like in a nursery rhyme -- otherwise one tends to stumble as they read it.

Natural drugs

Self healing of the mind
To forget that daily grind
forget that daily grind! (match rhythm, emphasize)

Dopamine rushing through
Away from worries I slew
I came, I saw, I slew (allusion to Caesar's veni, vidi, vici -- in English "I came I saw I conquered" and heroin which derives form "hero")

Oxytocin missing its bond
the Oxytoxic bond (poetic license, again match rhythm. s  bound is better than bond here, so maybe...)
by Oxytocin bound (better fit with following sentence -- here it means "bound by Oxytocin", so slightly awkward still)
For my love is not around
when love is not around (match rhythm)
(changing it like this implies that you NEED the drug when she's not around, which is what "missing" was saying -- but stronger)

(how about "the opiate I found"?)

I miss my horny drug dealer
Your body for natural healer

I would rewrite this as:
I'm horny for my dealer
her body is my healer

you should feel free to add articles to help rhythm or form (e.g. haiku) but normally you don't want them.

The most important sentence on writing in English, by Strunk:

Omit needless words

This shouldn't mean every poem is brevity, but certainly if the sentence sounds more awkward in rhythm, consider rephrasing it without the article

end result

Self healing of the mind
forget the daily grind!

when love is not around
The opiate I found

demands my horny dealer
her body is my healer

Author notes: this is a comment's on another's poem per contest] I find that reading out loud helps to make sure rhythm matches https://allpoetry.com/poem/15991919-Natural-drugs-by-Zetolgam https://allpoetry.com/contest/2781677-Help-me-improve