Plan B vs Levonorgestrel: are they the same?
Plan B is a commercial brand whose active ingredient is exactly Levonorgestrel. This page explains what that means in practice: where they differ (brand, manufacturer, price, available strengths), why they are clinically equivalent, and when the brand or an authorised generic is the better choice.
Are they the same?
Yes — Plan B contains Levonorgestrel as its active ingredient. Talking about "Plan B" in clinical terms is the same as talking about Levonorgestrel at the dose strengths 1.5mg. The differences from the authorised generic are brand, manufacturer (Foundation Consumer Healthcare), excipients, tablet appearance and price — not the active molecule itself.
When Plan B is used
プランBは生殖年齢の女性における避妊なしの性交または既知/疑われる避妊失敗後の緊急避妊に適応されます。72時間以内に最も有効であり、継続的避妊と比較して周期あたりの妊娠リスクが高く副作用があるため、定期的な避妊法として使用すべきではありません。臨床ガイドラインによれば、緊急避妊を繰り返し必要とする女性には定期的な避妊法に関するカウンセリングを提供すべきです。
Mechanisms compared
Because they share the same active ingredient, the mechanism is identical: プランBの主な作用機序は、LHサージ前に服用された場合に排卵を遅延させるか阻止することです。排卵がすでに起こっている場合、レボノルゲストレルは頸管粘液や卵管輸送にも影響する可能性がありますが、排卵後の効果は限定的です。プランBは確立された妊娠を中断させず、堕胎作用はありません。有効性は性交直後に最も高く、72時間の枠内で減少し、120時間まで一部の有効性が持続します。
Brand or generic — which to choose?
For most patients, authorised generics of Levonorgestrel are clinically equivalent substitutes for Plan B and typically cost substantially less. The practical differences are manufacturer, excipients (rarely matters except in specific sensitivities), tablet appearance and price. The brand is preferred by some patients for personal reasons or insurance coverage; the generic is the default when cost matters.
よくある質問
Is Plan B the same as Levonorgestrel? ▾
Clinically yes — Plan B is the brand and Levonorgestrel is its active ingredient. At equivalent doses (1.5mg) they produce the same effect. The difference is brand, manufacturer (Foundation Consumer Healthcare) and price.
Is generic Levonorgestrel as effective as Plan B? ▾
Yes. Authorised generics of Levonorgestrel must demonstrate bioequivalence to the brand. The active substance is the same; average effect is the same. Price is usually substantially lower.
Why does Plan B cost more than generic Levonorgestrel? ▾
The price difference reflects originator development costs, brand recognition and competition among generic manufacturers. The molecule is identical; the cost is not.
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