Well, if Ginny uses love potions on Harry in fanfiction, it might create chaos among their friends. Their friends, like Hermione, might sense that something is off with Harry's behavior and start investigating. This could lead to a big conflict within their friend group, as some might side with Ginny thinking she did it out of love, while others would be appalled by her using such unethical means.
In some fanfics, Snape may use a potion similar to the Felix Felicis, the luck potion. But instead of just bringing luck, this modified version could be used to change Harry's fate or the course of his actions. It could make Harry more inclined to make certain choices that Snape desires. Also, there could be a potion that can temporarily suppress Harry's magic, which Snape might use to keep Harry out of trouble or to protect him in a different way.
One problem is the lack of true consent. When a character is under the influence of a love potion, their feelings are artificially induced rather than being based on genuine emotions and choice. This can make relationships seem forced and unethical.
Well, in some fanfics, a character might be poisoned by a dark potion and the only antidote is a love potion. This shows an interesting interaction between different types of potions in the HP universe. Also, a love potion could be combined with a potion that gives the drinker special abilities, and this combination could lead to a character having the confidence to pursue their love interest. Another way they interact is when a love potion is used to break a curse that was placed on someone using a different type of HP potion.
One interesting fanfic could be about a young wizard who accidentally drinks a love potion meant for someone else. He then goes on a wild adventure trying to figure out how to reverse the effects while also dealing with the chaos it causes in his relationships. Another could focus on a potion - maker who creates a new type of love potion that has unexpected side - effects and how it impacts the wizarding community. There might also be a fanfic where a character uses a love potion to win the heart of their crush, but then realizes the moral implications of their actions.
In the fanfiction world, it could be a gift from a powerful being. There are many powerful wizards or magical creatures in the Harry Potter universe. Maybe one of them, seeing Harry's importance or just out of kindness, bestowed this immunity upon him to protect him from the potential chaos that love potions can cause.
The effects are usually quite extreme. The person who drinks the love potion falls madly in love with the first person they see. It's like their free will regarding love is overridden. For example, in some fairy tales, a character drinks a love potion and instantly becomes devoted to someone they may not have even noticed before.
In many fictions, love potions are often made with rare and magical ingredients. For example, in some stories, they might contain the petals of a special flower that only blooms once a century. Some may also include the scales of a magical fish or the tears of a mythical creature. These ingredients are combined in a specific way, sometimes with a chant or spell, to create the love potion.
Maybe he uses some special ingredients that others don't usually consider. For example, he might find a rare herb in the Forbidden Forest and use it in a potion to enhance its effect.
Morally, love potions are wrong as they violate a person's autonomy. A person has the right to choose who they love based on their own free will, and a love potion takes that away. It's like a form of mental manipulation.