Побічний ефект — не протипоказання.

In Ukrainian, the verb бути (to be) is usually omitted in the present tense.

So instead of saying the full equivalent of A side effect is not a contraindication, Ukrainian normally says:

Побічний ефект — не протипоказання.

The dash helps show the relationship between the two parts, especially in formal or written style.
A fuller version is possible:

Побічний ефект не є протипоказанням.

That means the same thing, but it sounds more explicit and somewhat more formal or emphatic.

Both are in the nominative case here.

This is common in simple identification/equation sentences like:

• Київ — столиця України.
• Це — проблема.
• Побічний ефект — не протипоказання.

So:

• побічний ефект = nominative singular
• протипоказання = nominative singular

In a version with є, the second noun is often put in the instrumental:

• Побічний ефект не є протипоказанням.

That is why learners often see both patterns.

Because не with nouns is usually written separately in Ukrainian.

So:

• не протипоказання = not a contraindication

This is similar to saying that something does not belong to that category.

Compare:

• Це не проблема. = This is not a problem.
• Він не лікар. = He is not a doctor.

There are some nouns where не- becomes part of the word permanently, but that is a different issue. In this sentence, it is ordinary negation, so не stays separate.

Word by word:

• побічний = side, secondary, collateral
• ефект = effect

Together, побічний ефект means side effect.

The adjective побічний agrees with ефект:

• both are masculine
• both are singular
• both are nominative

So this is a standard adjective + noun phrase.

Протипоказання means contraindication.

It is built from parts that roughly suggest something that speaks against using or doing something medically:

• проти- = against
• показання = indication / grounds for use

So протипоказання is the opposite of показання in a medical context.

This is a neuter noun. Its dictionary form is:

• протипоказання (nominative singular)

A learner should also know that many nouns ending in -ання / -ення are neuter.

Yes, absolutely.

Both are correct:

• Побічний ефект — не протипоказання.
• Побічний ефект не є протипоказанням.

The difference is mostly stylistic:

1. With the dash

   • shorter
   • very common
   • sounds like a definition or general statement

2. With є

   • more explicit
   • often feels more formal or technical
   • usually takes the predicate noun in the instrumental: протипоказанням

So the sentence you were given is natural and concise.

Because Ukrainian has no articles like English a / an / the.

So:

• побічний ефект can mean a side effect or the side effect
• протипоказання can mean a contraindication or the contraindication

The exact meaning depends on context.

In this sentence, English naturally uses the indefinite article:

• A side effect is not a contraindication.

But Ukrainian simply does not need any article words.

The normal, neutral order is:

Побічний ефект — не протипоказання.

This presents the topic first (side effect) and then says what it is not.

Ukrainian word order is flexible, but changing it changes the emphasis.
A reversed version would sound marked, unusual, or poetic unless the context strongly supports it.

So for a learner, the safest pattern is:

[topic] — [comment]

Here:

• Побічний ефект = topic
• не протипоказання = comment

The nouns simply belong to different grammatical genders:

• ефект = masculine
• протипоказання = neuter

In this sentence, that does not create a problem, because the two nouns are not required to match in gender.

What matters is:

• побічний matches ефект in gender, number, and case
• протипоказання stands on its own as the second noun phrase

So yes, you should notice the genders, but there is no agreement needed between the two nouns themselves.

Here it is understood as singular: a contraindication.

You are right that forms like протипоказання can look the same in singular and plural in some contexts, especially with nouns of this type. But in this sentence, the meaning is clearly singular because the statement is classificational:

• A side effect is not a contraindication.

If the speaker meant plural, the context would normally make that clear.

It sounds neutral-to-formal and especially natural in a medical or informational context.

The vocabulary is technical enough that it fits well in:

• medical advice
• instructions for medication
• healthcare articles
• doctor-patient explanations

It is still easy to understand, but протипоказання is definitely not very casual everyday vocabulary for most situations.